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Evaluation of Steel Bridges - Institute for Transportation

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1. 3 0 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Day 1 30 day daily statistical trends for Sensor 5 Figure 3 12 continued 96 Microstrain Microstrain 8 S 888 0 10000 20000 30000 40000 50000 60000 70000 80000 90000 100000 110000 Event Counts k 30 day event history for Sensor 6 240 220 Daily Maximum Daily Average Daily Average Fit 140 120 100 i B0 9 ki 2 2 40 20 SS Gish ak se a A 0 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Day 1 Daily 30 day daily statistical trends for Sensor 6 Figure 3 12 continued 97 240 220 8 pa gt Microstrain e 20000 _ 40000 _ 60000 _ 80000 100000 120000 140000 160000 180000 200000 220000 Event Counts m 30 day event history for Sensor 7 Daily Maximum Daily Average 5 Daily Average Fit Microstrain 98 4 7 0 12 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Day n 30 day daily statistical trends for Sensor 7 Figure 3 12 continued 98 Microstrein Microstrain
2. 146 Table B 6 Description of selected controls and indicators 6 View Hourly File VI 147 Table B 7 Description of selected controls and indicators in 7 Create Report From Single File VI and 8 Create Report From Multiple Files VI 147 B1 1 Preliminary DAQ VI shown in Fig B 1 i iii vi Vil viii X Enter a device name 71 The device name used here must match what was used during the hardware system setup Enter a sample rate 2 at which the data acquisition is to be performed number of samples per second Select the channels of a connected StrainBook 616 and if applicable a WBK16 expansion module to be activated 3 amp 4 More than one channel can be selected by Ctrl Mouse click Configure each channel 5 based upon the specific type of strain sensor being used Apply and select a calibration file which was created during the sensor calibration process by setting the LED 6 to true bright green and by assigning a calibration file path 7 Designate a folder directory 8 in which the data will be saved The recommended directory name is CASHM Folder Preliminary Data Folder Users can use the Browse button to display a tree of all directories available on the host PC Enter the time duration in control 9 for which each data file will be saved Start data collection by clicki
3. 112 1 0 110w 112 Lom 7 mra liom 7 no lt 10576 10800 11060 11200 11220 11595 ET 5 112 to Lom Counts Br Figure B 1 Screen shot of 7 Preliminary DAQ VI front panel B2 2 FFT PSD Analysis VI shown in Fig B 2 xi xii xiii xiv XV XVI xvii Select a data file from those that were saved in the Preliminary Data Folder by using the browsing tool in control 1 Under the FFT PSD Analysis tab control 2 enter a sample rate in Hertz 3 Note that the sample rate used here must be the same as the one used while acquiring the data Choose a time domain window 4 to be used in the FFT analysis and PSD development The recommended option is Hanning and is set as the default Run the program by clicking the run button 5 As soon as the run button is pressed the status indicator 6 will turn red indicating that the FFT PSD analysis is running Indicator 7 will display the data file read progress When the data file reading is completed the total number of sensors used during the preliminary data acquisition will be displayed Upon completion of the FFT PSD analysis the status indicator 6 will turn bright green indicating that PSD plots for each sensor are ready to be viewed Select a sensor with a mouse click within control 8 Then the indicator 9 wi
4. 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 1000 T 500 c o E 0 400 500 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2000 Moment ft kips Strain microstrain West Pier 1500 4 East Pier c 5 t o o gt 400 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 4 Moments and strain due to Iowa legal truck Type 353 B at the sensor locations with respect to the first axle position E 5 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 1000 9 500 5 gt 0 50 400 500 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2 000 Moment f kips Strain microstrain West Pier 1500 East Pier 1000 9 500 0 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 5 Moments and strain due to Iowa legal truck Type 3 3 at the sensor locations with respect to the first axle position E 6 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 1000 9 500 5 gt 0 I 50 400 500 1000 First Axle Position ft a Sensors 1 and 4 in the center
5. Differential Shunt resistor in Differential Load Resistor Lad resistor For the functions listed in the preceding table internal StrainBook configurations still apply as indicated on pages 6 8 through 6 11 6 14 Badge Contgurations 16 Users Manual 23 C3 Sensor Calibration Sensor Calibration To use the Sensoe Calibration Program you must first launch WaveView This can be done from shortcut on the desktop or by selecting WaveView from the Programs group accessed from the desktop Start menu WaveView holds user configured parameters that can be saved to disk The default configuration filename is WAVEVIEW CEG When Wave View starts up it proceeds to search the working directory for this file WaveView also holds defauk sensor calibration file The file holds the name of this calibration file so that all sensor calibration information from the last WaveView session is also loaded into WaveView during initial boot up If the default configuration file is found all the required setup information will be extracted from it and the application s main window will open When connection is established the application s main window will open with the default setting If these options fail a dialog box will ask if you want to open a different setup file Reference Notes For detailed Wave View startup information refer to the Wave
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7. 0815 The outcome of 3 Input VI is a binary file that contains input settings that are needed for operation of 4 MainDAQ815 VI It should be noted that 4 MainDA Q815 VI must be installed as a service program on the field PC Operating the program as a service allows autonomously resuming when the power comes back on in case of power outage During this installation process the time for which the program is forced to wait until the acquisition instrument is initialized must be defined The recommended pause time is 60 seconds Detailed procedures on installing 4 MainDAQ815 VI asa service program are provided in Appendix D The information presented in the following sections describes the detailed procedures pertaining to how 3 Input VI and 4 MainDA Q815 VI are operated 2 2 4 1 Input Information Settings for Main Data Acquisition and Processing Before 4 0815 can be activated for the main data acquisition and processing an input file that contains required information must be created with 3 Input VI In general three steps need to be completed 1 input entry 2 program execution and 3 verification First the user needs to enter the input settings Note that some procedures are the same as those used in running 1 Preliminary DAQ VI The required input information is as follows e Select the channels of a connected StrainBook 616 and if applicable a WBK16 expansion module to be activated 1 amp
8. 1 7 4 4 2 87 Figure 3 12 Monthly evaluation from on Nov 14 through Dec 14 of 2006 92 Figure 3 13 Hourly event histograms of typical weekday and weekend day for Sensor 4 bin width 5 TIROPOSIPATT 2 lao 100 Figure 3 14 Daily and weekly event histograms for Sensor 4 bin width 5 microstrain 101 Figure 1 BEC Analysis title screen on Bridge Information window sess 6 Figure A 2 General information options on Bridge Information window sssss 7 Figure A 3 Span Description window 5 oreet eterni ERI ER 7 Figure A 4 Section Properties Window iere eter dicte ertt 9 Figure A 5 Load iicet eee 11 Figure A 6 Analysis WEIBdOW eere te ae eq eom REG Vena 12 Figure A 7 Print Maximums Window price Nee eet nex aep QNUM DAE DU SiS 14 View Data Wy TOW ve Dead 15 Edburecic9 c Plot Wa We else 16 Figure B 1 Screen shot of 7 Preliminary DAQ VI front panel sse 3 Figure B 2 Screen shots of 2 FFT PSD Analysis VI front panel eee 6 Figure B 3 Screen shot of 3 Input Vi front panel uiuos eei uio 8 Figure B 4 Screen shots of 4
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10. o change the units h gnlight fe desired box the nevi parameters and then press Enter on the keyboard or selact another bae with the mouse Up to 5 characters be entered into this column To fill the entire column wath the valus of channel one make sure yas 15 selected in the Caibeate column Then dick on the column label with the mouse message box wil appaar Click on yas All channels wth the calibrata funcion enabled wil be filled Changing the units here vall also change Me units column in the Wave View Configurahan main window Used to label channels Sensor Label A Serial number oc other identifying label for the sensor be entered here Up to 29 be entered and 16 wil be displayed The 11 option ts evarlable for ths column soo StreinBock 6 16 User s Manual Software 4 17 27 4 12 Software I Changing the exctation voltage on any channel bebween and tour will chenge the value on all four towar channels Likewise changing the excitation voltage on any channel fhe through eight will change the value on all four upper chennels Changing the Voltage wil also change the Source Level column the Wave View Configuration man window Used for calibrating siran gages with the Name Plate calibration metod change this value select the Dox and enter number greater than 0 end less than 1000 The fill optio
11. 53 neach span 54 Ata designated location fun Analysis 57 Maximum Moment ft kips and Strain microstrain Location Truck Position xf b1 ft Span M M 3 Strain Strain 5 xift bif 152 46 36 5 294 80 0 52 B 5 126 3 55 243 0 52 M MQ Strain Strain 5 c ce 330 360 330 360 359 Span2 M M 3 Strain Strain 5 187 58 90 119 157 98 50 112 163 30 118 130 60 112 Span M M Qr Strain Strain J zu EN e c e 390 420 390 420 Span3 M Strain Strain 5 200 96 150 179 166 150 179 Spans M M Qr Strain Strain 5 di o c ce 450 480 450 480 Span4 M MG Strain Strain O 201 21 21 0 239 15912 240 249 166 210 239 131 240 249 Spang M M QJ Strain Strain 5 EF EE c a EN co a co 510 540 510 540 Spans M M 3 Strain Strain 5 201 22 270 294 59 13 309 299 309 300 166 270 131 300 10 M QJ Strain Strain O J 564 600 564 600 b In each span option Figure 2 8 continued
12. OskShi 2 A3 Cale Shb DEI Crewe 8 Figure D 2 Creating a new service program in the FireDaemon Pro Service Manager window D 2 S New Service Definition IE Progiam Settings Advanced Derendanciss Erwranmart Pre PostService Scheduling Service dentilication Short Name MarDAQES Display 040815 Custom Prefix Suing FiieQsemon Sen Desciiplion Application to Run az a Service Console Application Executable CASHM EXEM MainDAQ815 exe Working Directo SHM EXE Patameters Start up Time 60000 a Program tab New Service Definition Program Selbngs Advanced Dependencies Environment Pre Post Service Schaduling General Show Window Namal Load Order Group Legen Logon Account Interact with Desktop C Service Lfacycie Start Up Mode Automate v Upon Program Exit the Piogiam v FlapDelec on Disabled v Gracelu Shutdown C Shutdown Delay b Settings tab Figure D 3 New Service Definition window D 3 Ixxxiv Under the Settings tab in the New Service Definition window shown in Fig D 3b a Enable the Interact with Desktop option by clicking the check box if selected a green check mark will appear in the check box Set the Start Up Mode to Automatic c Set t
13. StrainBock 616 User s Manual Setup and Connecting to the Ethernet 5 3 4 Reference Note Adobe PDF versions of user manuals will automatically install onto y our hard drive as a part of product support The default location is in the Programs group which can be accessed from the Windows Desktop You can also access documents directly from the data acquisition CD via the lt View PDFs gt button located on the CD s opening screen STEP 1 Install the Software Install the software prior to connecting the StrainBook 616 to the Ethernet Ifyou have not already installed the software do so at this time Refer to the section entitled Software Instalfarion page 5 2 STEP 2 Determine the type of Network Connection To properly connect and configure a StrainBook 616 y cu must determine the type of network that the device will become part of This is because the type of network used has a direct bearing on the IP address of the device The four network types are as follows Dedicated Network with a direct cable connection from the PC to the device Dedicated Network making use of a network hub or switch LAN with a DHCP server Local Area Network with Dynamic Host Configuration Protocol LAN without a DHCP server Local Area Network with no Dynamic Host Configuration Protocol Bricf descriptions and illustrations follow Dedicated Network with a direct cable connection from the PC to the devi
14. b Section properties for Standard Steel option Figure 2 6 continued 13 Section Properties Deck C Non Composite E elastic modulus ksi E deck 3640 H height inches Composite H W 48 W width inches mlowa Beam Information LX Area 382 5 53 Bulb Tees LXB34 LXB50 Depth 39 LXB63 LXBB7 Y bottom 17 06 i LXC30 LXC46 LXC71 LXC80 62000 LXD45 LXD60 Sensor Location inches Q3 Gt 3 Gb Gt distance from top of beam Gb distance from bottom of beam 26 Click to Compute Properties OK Cancel Composite IN Composite 3N fom HM mE Ixc 2 9899691358 4 Ixc 10 6333421095 74 7 0026762294 4 Stop 1 8943838242 3 Stop 32 3258847229 1 3 Stop 76430614637 3 Sbot 25518939993 73 Shot 13920229242 _ Sbot 38186977038 c Section properties for Iowa P C option Figure 2 6 continued 14 Section Properties Deck E elastic modulus ksi C Non C it E deck 3640 H height inches Composite H fio Ww 48 W width inches AASHTO P C Beam Information Slab Beams Area 789 Box Beams Depth 54 Y bottom 2473 C Bulb Tees ke 260730 Sensor Location inches Q3 Gb Gt distance from top of beam Gb distance from bottom of beam 26 Click t
15. T T FP T T TF TP SWHONDLLS INHIALOSV LSVH 5 Sr HAST DNIOV3IH SSO3IO SIHNHAJLLS SIHALIS ISVH Wvdd 40074 ALV Td LSAM 9 INSALLOSV 15 79 65 LEPP IPS oje q 6 6 IMIA sSuurog juounnqy 194039 04 1903 0 006 49 09 t 49 46 GEL 80714 0 T a a X X VEL Td 49 06 41 X 01 porode L 0 90 0 92 GET X porode L WET Td 9 49 LX aL Id JAM X wel AIM X wel Id JAM EX AZT Td 942 41 X 0 porode L 0 90 V 0 92 GET X porode L EX 21 Td 949 GET X 182 714 0st goara 3 101145 5 Wald gorias 5 INSAIAOSV 66 3 2 Hardware Components Installation As described previously the basic hardware components include sensors the data acquisition hardware and a communication system The complete SHM system that was installed on the US 30 bridge uses an onsite computer to run the field monitoring software The selected sensors data acquisition hardware and computer equipment were installed at the bridge site during the fall of 2006 A brief description on the installation and connection of these components are provided in the following 3 2 1 Sensor Installation The selected quarter bridge strain gages were installed at strategic points on the bridge The locations of the strain gages were selected based primarily upon
16. 0 upto 10 spans Boundary Condition O Lett Exterior Support Interior Support Right Exterior Support Fixed C Pianed Aoller Pinned Roller C Pinned Roller Figure 2 4 General information options 10 M Span Description Span 1 Description Span Length ft 60 Member Selection C Prismatic Member Non Prismatic Member Member Type Member Cross Section Beam Material C 2sections 1 12 Define Steel C 3sections 11 to 13 C Standard Steel C Concrete C 4sections 11 to 14 C lowaP C 5 sections 1 to AASHTO P C Moment of Inertia ft 4 and Section Modulus ft 3 for each section E ksi 29000 Section Length ft Calculator 11 3371 51 2905 510 2905 AIL is Calculator 12 1939 S2 1904 S20 1904 A2L is Calculator 13 1972 530 1730 530 1730 Calculator 14 1577 54 1406 540 1406 Calculator 15 zm S5 550 EDN Figure 2 5 Span Description window 11 Section Properties Deck and W inches E ksi E deck 3640 Composite H o W 48 1 C Non Composite H and vv inches wl Tapered Flanges H2 We C Beam Angles C T Beem ZE EZ H4 W4 3 C T Beam w2 H5 WS Tapered Flanges Gt C Channel C Channel Sensor Localion inches Tapered Flanges
17. 18 Print Maximums Harir ircre 29 lw Analysis Maximums and Locations Find the Results 0 7 Truck moving er every Ne ul Anelysis 1 C designates locetan end Strain ricrostraun Tacs Poston m 152 45 36 zum 125 36 t 13 33 ec res Stan Sons waon t Strain 5 Sauna V is 9 Strain J Sirain 2 201 35 150 150 9 160 165 150 160 n2 eo p 15912 res 220 10 e 201 22 270 240 To t3 ro e 259 309 270 259 ats Span MO Strain Strain Spe MO Sirain MIO Mo ron Sven Spe MO Sirain Sront Spor MIO Mo strain 1 7 1 2 1 a em CE 192 62 16643 gt e 5 a When In each span option is selected Figure 2 9 Print Maximums Window 19 Print Maximums Maximums and Locations Frio the ruck maero f lnsach son f Al designed location titkom the support kaz
18. 240 220 00 Overload event threshold 180 vent s 20000 40000 60000 80000 100000 120000 140000 160000 180000 200000 220000 240000 260000 280000 Event Counts 0 30 day event history for Sensor 8 Dverload event threshold Daily Maximum 6 4 yr Bin ang oo 0 Go 1 b 0123 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Day p 30 day daily statistical trends for Sensor 8 Figure 3 12 continued 99 8007 7004 600 3 gt 2 2 gt 2 2 2 2 2 7 7 7 7 2 2 2 2 7 2 2 2 2 7 2 2 20 7 27 27 47 7 gt 27 27 27 27 27 27 47 07 47 47 7 7 7 07 07 07 47 47 47 47 47 47 47 7 47 47 47 47 7 _ 20 27 7 7 7 2 2 222222222222 5004 4004 4x 47 7 47 7 L7 L7 L7 7 47 47 7 47 47 17 T 07 7 7 gt 7 7 2 2 2 7 7 7 ap ap AP 7 7 07 47 07 47 47 7 7 7 7 7 7 7 Mmmm mmm mm m m e m m m p 7 m m m Frequenc
19. frame 45 which allows the user to choose the span s upon which the uniformly distributed load will be applied If users wish to apply a live load that is not available in the above a manual load generation can be performed This can be accomplished by selecting the Define option 42 which allows users to configure a truck with up to eight axles After defining the desired number of axles in the Number of Axles text box 48 a corresponding number of text boxes will appear in 49 and 50 where the specific configuration is entered 26 2 1 2 5 Analysis Window The analysis is performed in the Analysis window shown in Figure 2 8 This portion of the software allows the user to run the analysis and to view absolute maximum results The analysis is performed when the Run Analysis command button 57 is pressed Upon completion a prompt dialog box will appear indicating that the analysis was successfully completed The specific results generated by the software depend upon the options selected and the inputs entered For example the program will generate absolute maximum moments and strains at a location X which would have been specified in text box 55 as illustrated in Figure 2 8a if the At a designated location option 53 is selected By selecting the each span option 53 the program will generate the magnitudes 66 and locations 67 of the absolute maximum moments and strains in each
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21. ecce eee ee eee seen eese toos tete 151 C1 3 Ethernet Connection and System 1 eerte ee 152 C2 Bridge Configuration 163 C3 Sensor Calibration 5 en ro nee evo TS PE UR SERE UP ee 172 C3a Sensor Calibration Example 4 ecce ee esee eee eese eese ee sese ense seen se eese os ee eese eesoe 178 For more information product manuals can be downloaded from IOtech website at www iotech com C 1 C1 Setup and Connecting to the Ethernet CI 1 System Requirements Setup and Connecting to the Ethernet 5 System Requirements 5 1 Software Installation 5 2 Ethernet Connection and System Power up 5 3 System Requirements Before setting up the hardware or installing the software verify that you have the following items e StrainBook 616 data acquisition system Power supply with cord see power note below Dataacquisition CD In addition verify that your computer meets the following minimum requirements Intel Pentium III processor 10 100BaseT Ethernet port 64 MB memory 100 MB hard disk space Monitor SVGA 800 x 600 resolution One of the following Microsoft Windows operating systems Windows 2000 Windows XP Windows NT Power Note StrainBook requires an input voltage between 10 and 30 VDC The DC source should
22. lix lxi lxii Ixiii Select the directory 1 in which the hourly data files are archived The default is set as CASHM Folder 3 Data File Folder If users want to access an hour file received via email the path to the folder that contains the received file must be selected Select a monitoring period 2 The number in the text box indicates the hour since monitoring began starting with zero For example if the user wants to open an hour file that contains the event history obtained during the first hour of monitoring 0 must be entered if the user wants to access a hour file occurring 56 days 3 hours later the user would enter 1346 To view the data file in an Excel Worksheet set the LED option 3 to true bright green Configure the histogram setting 4 This option allows users to change five variables number of bins and maximum and minimum bins for both positive and negative events Press the Click to View Hour File control 5 to execute the program The event history and histogram monitoring period and alarm messages will be displayed in the indicators 6 7 and 8 respectively The event history and histogram for each sensor can be accessed by selecting the tabs designated for each sensor Stop the program by pressing STOP control 9 B 12 4 Onal 106 Merosran 101 Meroetran 11 15 2006 01 17 AM Sensors 110 MCrogyan Figure B 6 Screen shot of 6 View Hourly File
23. Composite option is selected in 720 The material properties and dimensions of the tributary deck are defined in the Deck frame 21 Note that frame 21 will only be enabled if the Composite option is selected The program will compute section properties when the Click to Compute Properties command button 26 is pressed The results are automatically copied when the OK command button 27 is pressed into 13 14 and 15 The section modulus for each segment will be computed at the locations specified in the Sensor Location frame 25 Section Properties window for user definable cross sections The window shown in Figure 2 6a will be called when the Define option in the Member Cross Section frame 9 is selected It allows users to compute section properties for general section types Options for nine general section types are provided as follows e Beam e Beam Tapered flanges e Beam Angles e T Beam Tapered flanges e Channel e Channel Tapered flanges e P C shape e Rectangular shape Depending upon the option selected in the Define frame 22 a corresponding graphic representation will be displayed in the graphic display indicator 23 Dimensions for each shape can be defined with the text box controls provided in W frame 24 where the letter H represents vertical dimensions and W represents horizontal di
24. In general one may use BEC Analysis for 1 analyzing beams or girders under moving loads 2 computing absolute maximums in each span or at a desired location on a model bridge and 3 generating envelopes of maximum moments and strains The second task involved developing the field data collection and analysis software that integrates with select data acquisition hardware The general background information and the methodology used during the development and the components and features of the field 102 monitoring software were described in Section 2 2 In addition the descriptions on the hardware system within the SHM system were presented in Section 2 3 The field monitoring software was developed to specifically function with IOtech instrumentation hardware The software was designed to collect process and evaluate the measured response of a bridge Its use will allow bridge owners to quantitatively monitor a bridge for potential damage as well as gradual changes in behavior The field monitoring software consists of three groups of programs 1 a preliminary data acquisition and analysis component that is intended for identifying basic characteristics 2 a main data acquisition and processing component intended for data collection reduction and evaluation processes and 3 a report generation component intended for presenting results to the user Each group of programs was designed to be accessed at any time The preliminary data acqui
25. Lowell F Greimann Bridge Engineer Bridge Engineering Center Iowa State University Doug L Wood Manager Structures Lab Department of Civil Construction and Environmental Engineering Iowa State University Research Assistant Yoon Si Lee Authors Brent M Phares Terry J Wipf Yoon Si Lee and Justin D Doornink Sponsored by the Iowa Highway Research Board IHRB Project TR 493 Preparation of this report was financed in part through funds provided by the Iowa Department of Transportation through its research management agreement with the Center for Transportation Research and Education CTRE Project 03 135 A report from Center for Transportation Research and Education Iowa State University 2711 South Loop Drive Suite 4700 Ames IA 50010 8664 Phone 515 294 8103 Fax 515 294 0467 www ctre iastate edu TABLE OF CONTENTS ACKNOWLEDGMENTS wis als UE Eon Ted OR GRO iR XI EXECUTWE SUMMARY rc tig e a cma alu XIII Dg STP RCC TION srne noie SUR AND Nd espe 1 TT Bae OR OUI ASAS 1 1 2 Objective PEOQUCE ocio tdi ho 1 T S Report Sonteeeeee 2 2 STRUCTURAL HEALTH MONITORING SYSTEM eerte 3 2 1 Structural Analysis Soft ware ie ste se e se e 3 2 2 Field Monitoring vete sn d o uel Rit 28 2 De Hardware SYSTEM ees RE 60
26. Strain microstrain West Pier T900 East Pier 1000 500 Moment or Strain 500 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2000 1500 Moment ft kips Strain microstrain West Pier East Pier 1000 500 Moment or Strain 500 350 400 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 11 Moments and strain due to HS 20 truck 3 axles 25 ft at the sensor locations with respect to the first axle position E 12 2000 Moment ft kips Strain microstrain West Pier 1900 4 t o E o gt 400 500 4 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2 Moment ft kips Strain microstrain West Pier 1500 East Pier 1000 2 500 o E gt 0 350 400 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 12 Moments and strain due to HS 20 truck 3 axles 30 ft at the sensor locations with respect to the first axle position E 13 2000 1500 4 1000 4 Moment or Strain e Moment ft kips Strain microstrain West Pier East Pier 500 1000 2000 50 100 150 200 250 300 350 First Axle Position ft a
27. Therefore users need to make appropriate changes on the security settings so that the execution program 4 0815 is unblocked Since the security settings may vary depending on Windows types 2000 XP NT etc and virus scan software used users may need to consult with a system analyst to resolve this o The check mark on the status check box turns red and a message appears on the message box along with an error code This indicates that the network connection is either unavailable or not established It should be noted that this error will not cause the program to stall or stop other functions except the email will still be functioning The program is programmed such that when an error related to network connection occurs the program will skip that step and carry on other tasks Also note that since all data files created by the program will be saved in 3 Data File Folder in the main directory users can always retrieve the data files manually Available disc and memory space on the field PC The total used and free available disc and physical memory space of the field PC will be displayed in Bytes in the Disc Memory Space indicator 5 If the user desires to change input settings or restart reset the program stop the program by pressing the STOP control 6 set the Reset control LED option in 7 to true bright green and re run the VI by pressing the Run control 9 These actions
28. VI front panel B7 7 Create Report From Single File VI shown in Fig B 7 and 8 Create Report From Multiple Files VI shown in Fig B 8 Ixiv Select the directory 1 in which the data files are archived The default is set to C SHM Folder 3 Data File Folder lxv In the Monitoring Period control 2 select data file s to be plotted and processed for the report generation See Note 1 below for detailed description lxvi To view the data file in an Excel Worksheet set the LED option 3 to true bright green Ixvii Select the print options 4 This allows the user to print the report either or both in a paper copy or and in PDF format given that corresponding option s are selected bright green e Select the report content options 5 This allows the user to choose the contents that will be included in the report Four options are available e Strain histogram numeric table numerical count of events in each bin where the bin size is specified by users f Strain histogram graph graphical representation of numerical count of events g Statistic Trends numeric table numerical values of absolute maximum events average events hourly or daily depending upon the data file selected and average trend line over the selected monitoring period h Statistic Trends graph graphical representation of events over the selected monitoring period B 13 lxviii Configure the event histogram variables 6 Thi
29. a prompt dialog box with a text message Analysis Complete will appear Click OK in the dialog box to view the maximum moments and strains and the corresponding locations which will be displayed in the correct format according to the option selected in step xviii Click Next 4 to move to the Print Maximums window 69 shown in Fig 7 Set the top and left margins 70 to be used Click Print 71 to print the image displayed in the display box 73 Click View Data 72 to move to the View Data window 74 shown in Fig A 8 Check the data display box 75 for moment and strain vs truck position analysis results or envelops Click Save to a File 76 to save the displayed data to a text file for later retrieval When prompted use the browse button to specify the directory and type the name under which the data file will be saved Click Plot Data 77 to move to the Plot window 78 shown in Fig A 9 Set the top and left margins 70 to be used Click Print Plot 79 to print the image displayed in the display box 80 Click Back 4 to move back to the previous window or Exit 64 to terminate the program A 13 cite bbb kele sles stele bal akl kill sl a When In each span option is selected b When Ata designated location option is selected Figu
30. dedicated networks only The StrainBook 616 Ethernet port typically requires 30 seconds after power up to configure before the unit can be accessed via the network If using a LAN Local Area Network which has DHCP server skip this section and continue with STEP 7 Configure and Test the System using DagConfiguration Applet page 5 11 If using LAN Local Area Network which has no DHCP server skip this section and continue with STEP 6 Configure Device Network Settings using DagiPConfig page 5 10 1 Open the Control Panel by navigating from the Windows Desktop as follows Start Menu gt Settings gt Control Panel 2 Double click the Network and Dial up Connections icon 3 Double click the Network Connection icon for the network StrainBook 616 is connected to StrainBoowS16 Use s Manuel Setup and Connectingtothe 5 7 C 8 4 Inthe Local Area Connection Status box previous figure click on the lt Properties gt button The Local Area Connection Properties box will appear following figure Local Area Connection Properties 5 Double click the Intemet Protocol component previous figure The Internet Protocol TCP IP Properties box will following figure 53 Setup and Connecting 0 the Ethernet StrainBaclo6 16 User s Manual C 9 Configure the Computer s TCP IP settings as follows 6 Select the Use the follo
31. iew PDF The document be accessed from the data acquisition CD via the lt View PDFs button on the CD s opening screen The WBKIG LC Load Cell Shunt Cal intemal option board may be required to calibrate load cells and transducers that have internal shunt cal resistors Sce the VRRIGLC section of chapter 6 for details m v 565 No D Bypass 1000 DC 100V No No 0 1000 DC 100 om v Sm 0 Bross Tomo oC 100 Albie WaveView Configuration Main Window Top and Sensor Configuration Calibration Window Bottom 4 8 Sotware StranBook 16 User s Manual C 24 To open the Sensor Configuration Calibration window click on WaveView s Sensor Calibration button The button is depicted at the left and pointed out in the upper portion of the previous figure Y ou can also open the window from WaveView s System pull down menn You can use the Sensor Configuration window s File pull down menu to Load am Existing Configuration This option opens standard dialog box that allows you to select and open the desired file Sensor Configuration Main Components Gage Sensidy Shut Bi cantos Reiter H shy ste LH N H i 4 Me H A 1 Het Sensor Configuration Calibration Window Sensor Configuration Toolbar and Pull Down
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33. 00057 00521 00001 0054 0005 0052 0 p osuas plousauu 1 3uaA3 9T Glosuss gjosues 105 6 ojosues siosuas elosuas 2105096 1205095 J suai jeans yena 190188 quaseld 0 Aeq yeayspeaids ox SUNG wuoday aga do Juud e juondo auud step aparan pourad Bunoyuow Japjo4 EPIO WHS AH sai 140d23 9382415 5001 d 5 Hod y 838815 8 4 45 2 2 3 1 Preliminary Data Collection and Storage 1 Preliminary DAQ VI allows users to acquire a small amount data for immediate viewing storage to the hard disk and for use within 2 FFT PSD Analysis VI to configure filter parameters Illustrated in Figure 2 14 is a typical setup for Preliminary DAQ VI Three steps a basic setup on input parameters b program execution and c results verification are involved in using this program The first step requires users to input parameters in controls 1 though 9 that are shown in Figure 2 14 as follows e Enter a device name in control 1 The device name used here must match what was used during the hardware system setup e Enter a sample rate 2 at which the data
34. 1 4 Bridge Shunt Rd cc ated e 09 S N 50v 2 000 57983 350 3000 0 0 0 3000 0 Strain Gage 1 4 Bridge Mot Calibrated e CH10 S N 50v 2 000 57983 350 0 0 3000 0 OW 7 Sensor Bridge Calibration Type Type Method PtMen Not Calibrate E SIN 2PtMan NotCalit E S N 00 2 Pt Man Not Document Figure C 2 C 31 C 32 APPENDIX D Installation of 4 MainDAQS15 EXE as a Service Program D 1 lxxx Install FireDaemon software Ixxxi Double click on the FireDaemon Service Manager icon shown in Fig D 1 Ixxxii In the FireDaemon Pro Service Manager window go to Select in the menu bar and select New option as shown in Fig D 2 Ixxxiii Under the Program tab in the New Service Definition window shown in Fig D 3a Type in the name of a service program to be created using alphabetic numeric characters only in the Short Name and Display Name text boxes available in the Service Identification Program frame b Using the browse tool available select the EXE program 4 MainDAQ815 EXE to be installed as a service program By doing this its working directory will automatically be assigned c Enter the start up time the time for which the program is forced to wait before it automatically resumes in the Start up Time text box 60000 ms is recommended which is equivalent of 60 seconds Process Uz
35. 11 47 13 109 10 88 10 68 11 73 10 106 10 Day 6 110 10 37 12 48 13 113 11 94 11 67 11 75 11 100 11 Day 7 137 10 51 11 53 12 134 11 112 10 80 10 101 10 110 10 8 98 8 37 11 46 12 104 8 85 8 67 8 72 7 96 8 Day 9 165 10 41 12 45 13 109 9 156 10 84 10 74 8 103 9 Day 10 94 9 35 13 45 14 108 9 79 9 67 9 69 8 102 8 Day 11 82 8 34 10 39 11 103 8 75 8 54 7 62 7 91 7 Day 12 110 10 39 12 48 13 145 11 96 10 69 11 86 10 122 10 Day 13 119 10 38 12 52 14 115 11 124 10 71 11 86 11 103 11 Day 14 109 10 39 11 53 13 103 11 91 10 70 11 81 10 111 10 Day 15 130 11 78 12 91 14 129 12 114 11 69 11 82 11 100 11 Day 16 109 10 37 12 4 3 108 11 108 10 69 11 67 10 94 10 Day 17 101 9 38 13 46 14 106 9 87 9 66 9 69 8 99 8 Day 18 97 8 49 12 45 12 98 8 77 8 90 8 82 7 90 7 Day 19 104 10 35 11 45 12 109 11 90 11 65 11 71 10 104 10 Day20 134 11 62 12 48 14 150 12 10211 103 12 116 11 129 11 Day21 107 10 40 11 41 13 129 10 96 10 69 11 74 10 134 10 Day22 106 10 35 12 45 14 141 11 102 11 66 12 72 11 151 10 Day23 126 10 50 11 54 13 125 10 99 10 92 10 90 10 131 10 Day 24 87 9 35 12 45 14 112 9 85 9 63 9 73 8 99 8 Day 25 86 8 36 11 39 12 96 8 79 8 57 7 62 7 84 7 Day26 108 10 44 11 43 13 118 11 97 10 75 11 69 10 105 10 Day27 109 10 40 12 46 14 129 11 98 10 68 11 70 11 109 10 Day28 103 10 39 11 43 13 111 10 90 10 65 11 72 10 98 10 Day29 141 10 48 12 58 13 17411 120 10 96 11 97 10 167 10 90 Table 3 6 Number of identified events bin width 20 microstrain Sensor Min b
36. 800000 b Select the Auto IP Setting radio button Note that the IP Address of the StramBook 616 will automatically be calculated and displayed in the IP Address field as indicated in the following left hand figure c Click the lt OK gt button 816 Tad E16 Test Harbus Doo Demesa Serie SedNwbs moi 00 Seita SSS Sting 4 Seting Seting Sating For DEDICATED Networks For LAN with DHCP Server Networks Configuration Properties Dialog Boxes Users of LAN with DHCP Server Networks follow these 3 steps The Dagi Config applet provides the Serial Number and the IP Address of the device Users of LAN with DHCP Server Networks will need to enter both numbers in the Dag Configuration Properties dialog boxes previous right hand figure Page 5 10 includes instructions for accessing DagIPConfig If needed refer to the upper right hand figure in regard to radio button and data entry locations Seta dover te wen ir charge b oder a Enter the base 10 version of the Serial Number of the StrainBook 616 b Select the Manual IP Setting radio button c In the IP Address field enter the IP address Partial View of DagI P Config E Showing IP Address amp Serial Number d Click the lt OK gt button Provide your networ
37. AASHTO Specification 3 Thus several load cases with different rear axle spacing were considered For analyzing the model bridge subjected to the truck train loadings several cases were considered in terms of a span or spans loaded with the uniformly distributed load of 0 64 kips ft For example when analyzing the model bridge at the sensor locations in the west end span the uniformly distributed load was applied in the west and east end spans as it generates larger maximum results than when one or all spans are loaded Similarly for analyzing the model bridge at the sensor locations in the center span only the center span was loaded with the uniformly distributed load Note that besides the uniformly distributed load a concentrated load of 18 kips was applied to the model bridge as a moving load The absolute maximum positive moments and strains at the sensor locations as well as the corresponding first axle positions for each loading case are presented in Tables 3 1 and 3 2 The plots of the theoretical moments and strain due to each load are presented in Appendix E Once the analysis of the bridge was completed and the absolute maximums due to each loading case are determined the overload event thresholds for the plate girders were determined For this demonstration the threshold was set as the least absolute maximum strain among those resulting from running all the design truck loads As can be determined from the information in Tables
38. As a result the program can determine the absolute maximum positive and negative moments and strains either in each span or at a designated location In addition envelopes can be generated The envelopes contain the extreme values both positive and negative of moments and strains along the length of a model bridge 2 1 1 General Methodology As the accessibility of powerful computers has become more common the use of matrix algebra has become more commonplace Thus the analysis algorithm used in BEC Analysis is based on classic beam theory and the direct stiffness method of matrix structural analysis The stiffness method is one of the most popular methods used in computer structural analysis programs and its formation is well published Thus it will be only briefly outlined here Inherent assumptions used in developing the analytical methods are as follows e All materials are assumed to behave elastically Plane cross sections remain plane e All elastic deformations are relatively small e A fixed support is defined as an end condition capable of resisting end moment without rotation while a pinned roller support is one in which there is no resistance to angular rotation and thereby no end moment For a composite sections the moment of inertia of the entire transposed section is used e Non prismatic spans may be approximated with stepped prismatic members e The analytical methods used in BEC Analysis are the same as the
39. County IA carrying US30 over the Skunk River near Ames IA The complete SHM system that was installed on the bridge uses an onsite computer to run the field monitoring software 1 process collected data and monitor for events and notify users any alarm events The selected sensors data acquisition hardware and computer equipment were installed at the bridge site during the fall of 2006 Prior to the running the field monitoring software the overload event thresholds for the sensors installed on the plate girders were determined using BEC Analysis In each run the bridge was subjected to various moving loads that include Iowa legal trucks H 20 truck HS 20 truck and truck trains After filter parameters were determined and all input settings were established the main program designed for data acquisition and processing 4 15 VI was initialized at approximately 3 pm on November 14 2006 after which continuous data collecting and processing have been completely autonomous and have required no intervention except when reviewing and generating evaluation reports The contents in the evaluation report that was generated were reviewed and several observations and interpretations were made for overall bridge performance during the thirty days of monitored period 103 4 2 Conclusions The following conclusions can be made regarding the development installation and the overall performance of the SHM system e The developed
40. MainDAQS15 VI front panel eee 10 Figure B 5 Screen shot of 5 View Strain History VI front panel sse 12 Figure B 6 Screen shot of 6 View Hourly File VI front panel essere 13 Figure B 7 Screen shot of 7 Create Report From Single File VI front panel 15 Figure B 8 Screen shot of 8 Create Report From Multiple Files VI front panel 16 Figure D 1 FireDaemon Service Manager icon sioe deae Sedes 2 Figure D 2 Creating a new service program in the FireDaemon Pro Service Manager window 2 Figure D 3 New Service Definition toe tete eoa na p ande 3 Figure D 4 Prompt dialog box eate dte etr Ee aa 4 Figure D 5 FireDaemon Pro Service Manager window service MainDAQ815 installed 4 Figure E 1 Moments and strain due to Iowa legal truck Type 3 at the sensor locations with respect to the first axle position aoi aes ces te art hen ie st eater nda dede eene adea 2 Figure E 2 Moments and strain due to Iowa legal truck Type 4 at the sensor locations with respect to the first axle position e eg acest d i Bid eee 3 Figure E 3 Moments and strain due to Iowa legal truck Type 352 A at the sensor locations with respect to the first axle position 4 Figure E 4 Moments and strain due to Iowa legal truck Type 353 B at the sensor location
41. Name of a StrainBook 616 assigned during IOtech software installation described elsewhere 5 Sampling Rate Control Sampling rate at which strain records are collected Hz number of samples per second 6 Impact Event Threshold Ratio of the absolute difference between the magnitude Control of an event and that of the event detection threshold with respect to the time difference between a start index and a peak index in a strain record 7 Event Detection Plus and minus event detection thresholds within which Threshold Controls no peak or event will be detected Microstrain 8 Overload event Thresholds that are used to determine overload events for threshold Control each sensor Microstrain 9 Email Options Controls Options that allow users to receive collected information via email 10 Email Inputs Control Email addresses and mail server that the collected information are sent from to 11 Calibration File Path to a calibration file created during calibration Controls process see Appendix C and a LED option to apply it 12 Raw Data Folder Directory into which the raw strain data file will written Control 13 Data Process Folder Directory into which the raw strain data file will be Control moved for processing 14 Data File Folder Control Directory into which reduced data files will be archived after being processed and evaluated 15 Filter File Path Control Path to a file that contains event detection thresholds and filter parameter
42. THOSNAS 7 9 YOSNAS pue y suonoos YIM URT 07591 0 67 NOLLOHS V NOLLOHS LSVH 5 Jald 15 5 LSAM 5 INSIALLOSV LS3A 69 b Hardware components inside the cabinet Figure 3 5 Environmentally controlled cabinet containing the monitoring equipments 70 3 3 Determination of Overload Event Threshold As previously mentioned the primary structural members are the two plate girders as the stringers are supported by the floor beams which are then supported by the plate girders Thus it was decided to only monitor the plate girders for identification of alarm events while both the plate girders and stringers are monitored for changes in behavior This section demonstrates how alarm events for the plate girders at the sensor locations were determined using BEC Analysis The plate girders in each span were divided into sections as they contain different section properties along the members To this end the west and east end spans were divided into three sections while the center span was divided into five sections as illustrated in Figure 3 6 Note that the cross section dimensions for the sections with variable size flanges tapered regions were assumed to be at the middle point in each region Based upon the detailed plan information the following input parameters were established e Number of spans 3 e Boundary conditions pinned rol
43. acquisition is to be performed number of samples per second e Select the channels of a connected StrainBook 616 and if applicable a WBK16 expansion module to be activated 3 amp 4 More than one channel can be selected by Ctrl Mouse click e Configure each channel 5 based upon the specific type of strain sensor being used e Apply and select a calibration file which was created during the sensor calibration process by setting the LED 6 to true bright green and by assigning a calibration file path in control 77 e Designate a folder directory 8 in which the data will be saved The recommended directory is C SHM Folder Preliminary Data Folder as is shown in control Z8 in Figure 2 14 Users can use the Browse button to display a tree of all directories available on the host PC e Enter the time duration in control 9 for which each data file will be saved Once the above setup is completed data collection can be initiated This step involves two controls and five indicators 10 through 16 shown in Figure 2 14 as follows e Start data collection by clicking on the START control 10 e Check the acquisition status in indicator 11 When the START control is pressed it searches the data acquisition instrument specified in control 1 One of the following situations will occur o check mark on the status check box stays green and indicators 12 13 14 and 15 will displ
44. and 15 in the Span Description window 19 or Cancel 28 to cancel the actions performed here e Scenario 2 Figs A 4b 4c and 4d when the Standard Steel Iowa P C or AASHTO P C option is selected in 9 a mo Same as step a in Scenario 1 Same as step b in Scenario 1 Select the desired cross section shape among the available options in 32 35 or 37 Corresponding contents for the selected section type will be listed in 33 36 or 38 Select a member from the list box 33 36 or 38 with a mouse click when selected it will be highlighted in blue The corresponding cross section information will be displayed in 34 Same as step e in Scenario 1 Same as step f in Scenario 1 Same as step g in Scenario 1 om vmm gt b Section properties for Standard Steel option Figure A 4 Section Properties window xii xiii Section l ropert es scc moten vc H begh ect T ncn howe PIC Dean racer eter E DUO DS 34 N 27 xf 7 Y botsw 17 06 be Satin LOCA CF af 36 OF om ci ber y Ci mace fom bare cf sem Nave Corpo ue Carga uw F4 w Rines 30 bc 4 xr 6070921005 4 Sy inks Stet c 20 eim
45. and data acquisition Reference Notes Although the signal conditioning aspect of the WBK16 is inherent in the StrainBook 616 and is therefore discussed in this manual specific WBK16 documentation is contained within the WBK Options Manual p n 489 0902 Note You can access PDF documents directly from the opening screen of the data acquisition CD via the lt View PDFs button StranBookis16 User s Manual Setup and Connechng to the Etharnet 5 13 C 14 C2 Bridge Configuration Bridge Configurations 6 Introduction 6 1 CN 115 Headers Associated Jumpers and Plug In Options 6 2 Bridge Applications 6 3 Excitation Connection 6 5 Low Pass Filter Customization 6 7 Ful Bridge 6 8 Half Bridge 6 9 Three Viire Quarter Bridge 6 10 Connecting to the DB9 Channel input Connector 6 12 177 Strain Gage Cable 6 12 189 DBS Adapter Option 6 13 WBK16 LC Load Cell Shunt Cal Internal Option 6 15 CN 115 1 User Configurable Plug In Card Option 6 20 Introduction The strain gage is connected to the amplifiers through the Bridge Completion and Shunt Cal Network This network consists of user supplied user installed resistors for bridge completion Several combinations of resistors and 3 different shunt values may be installed simultaneously External connector tie points and the programmable Input Configuration amp Cal MUX determine
46. be filtered but not necessarily regulated The TR 40U AC to DC power adapter is recommended for AC line applications However StrainBook can be powered from any isolated 10 to 30 VDC source of al least 25 W Before plugging the unit in make sure the power switch is in the 0 OFF position GND Power Input DINS Connector If you will be using an AC to DC power adapter such as the TR 40U plug it into an AC outlet then connect the DINS end of the cable to the StrainBook s 10 to 30 V DC Input connector If you are using another power source such as a battery ensure the leads are connected to the proper DINS pins indicated in the figure Do not exceed the 5 maximum DC current limit of the POWER IN DINS connector StrainBookt User s Manual anra Setup and Cannecting to the Ethemet 5 1 C 2 C1 2 IOtech Software Installation Software Installation 5 2 pP Remove any previous version Wave Hew driver This cun be done through Microsoft s Add Remove Programs feature Start Windows Close all running applications Insert the Data Acquisition CD into your CD ROM drive and wait for the CD to If the CD does not start on its own click the desktop s Start button b choose the Run command select the CD ROM drive then select the setup exe file gd click lt OK gt An Opening Screen will appear Click the ENTER SETUP button From the hardware selection screen
47. bottom of the beam This section 1 modulus is either manually entered by users or computed by the Calculator 12 15 Si Control Section modulus for each segment at a sensor location specified in 25 If a sensor location is not specified the default will be the top of the beam This section modulus is either manually entered by users or computed by the Calculator 12 16 Section Length Frame Length of each segment This will only be enabled if Non Prismatic option was selected in 7 17 Section Display General graphic representation of how a member will be segmented in each span A different graphic will be displayed according to options selected in 7 and 8 18 Back Command Moves to the previous window 19 Section Properties Window Called when Calculator 12 is pressed A different window will be activated depending upon the options selected in 9 A Section Properties window calculates geometric section properties for general section types user defined and also provides section properties for standard steel Iowa P C and AASHTO P C sections When completed moment of inertia and sections modulus values will be automatically copied into 13 14 and 15 in the Span Description window 20 Composite Option Frame Allows generating section properties for a beam that is either composite or non composite with the deck 21 Deck Frame Allows users to specify modu
48. change in performance of the bridge Rather they simply represent individual events induced by heavy vehicles in different days e The daily average of identified event is less likely to show variability to single heavy traffic event Therefore a gradual performance change can be estimated or predicted by investigating the daily average and the slope change over time By 88 reviewing the daily average of identified events for each sensor as illustrated in Figure 3 12 it appears that the overall performance of the bridge was consistent for the monitored period as would be expected This observation was made by investigating the slope change Table 3 4 of the daily average fit curve that is essentially zero for all sensors If the condition of the bridge starts to change due to deterioration etc without a significant change in traffic pattern the structural response of the bridge will also change and therefore the daily average is expected to change e Comparing the numerical counts of events identified in the north plate girders with those in the south plate girders Sensor vs Sensor 4 in the center span and Sensor 5 vs Sensor 8 in the west end span more events were identified in the south plate girder than in the north plate girder This was originally expected as more traffic is expected to travel in the driving lane south lane than in the passing lane north lane Similar results can be observed from comparing the num
49. designed for preliminary data acquisition and analysis while 3 Input VI and 4 15 VI are intended for use during main data acquisition and processing The remaining programs are used for viewing and or generating reports Included in the title of the first four programs 1 2 3 and 4 is a number that indicates the order in which they should be executed The other four programs 5 6 7 and 8 can be executed only when needed and in any order Each program features a user interface and visualization command controls that are facilitated by tools contained in the program s graphical environment Presented in Figure 2 13 is a general flowchart that illustrates the overall procedures undertaken by the field monitoring software Screen shots of each program are shown in Figures 2 14 through 2 21 Note that the front panels of each program contain two different types of displays controls and indicators Controls are devices that provide input and supply data to the programs Indicators are devices that display output and or data generated by the programs Brief descriptions on select controls and indicators of each program are presented in Appendix B 32 2 2 2 2 Required Initial Setup The field monitoring software can be used only after a completing the IOtech software installation hardware system setup and sensor calibration and b creating a main directory SHM Folder that will contain input files and four sub directories f
50. developed such that it can present summarized information to users To this end algorithms were added so that reports can be automatically generated in three formats Microsoft Excel Worksheet PDF and hard copy These reports are flexible and their contents can be modified to provide only the information desired Regardless of the format each report can contain information as follows e Monitoring period during which presented outputs are given e Event history that presents each recorded event e Event histogram e Statistical trends of events including absolute maximum and average e Summary of messages regarding alarm events 2 2 2 Components of the Field Monitoring Software and Required Initial Setup 2 2 2 1 Components of the Field Monitoring Software There are three groups of programs included in the field monitoring software 1 a preliminary data acquisition and analysis component that is intended for identifying basic characteristics 2 a main data acquisition and processing component intended for data collection reduction and evaluation processes and 3 a report generation component intended for presenting results to the user Each group of programs is designed to be accessed at any time The preliminary data acquisition and analysis tools assist in reducing noise and detecting events This process involves establishing the parameters that will be 31 used during the data processing and evaluation processes that occur in
51. digital filer with an appropriate cutoff frequency At the end of the process a text file containing filter parameters and event detection thresholds for each channel is created The followings describe each step involved in running 2 FFT PSD Analysis Three primary tasks are performed within 2 FFT PSD Analysis VI a identification of dominant frequencies through a FFT PSD analysis b idealization of filter parameters and 47 plotting the resultant strain history and c creating a filter parameter file As illustrated in Figure 2 15 each task is performed in three different program tabs The first task involves opening a data file acquired with 1 Preliminary DAQ VI and then running the FFT PSD analysis The following steps are required to perform this task 12 10 11 Select a data file from those that were saved in the Preliminary Data Folder by using the browsing tool in control 71 Under the FFT PSD Analysis tab control 2 enter a sample rate in Hertz 23 Note that the sample rate used here must be the same as the one used while acquiring the data Choose a time domain window 4 to be used in the FFT analysis and PSD development The recommended option is Hanning and is set as the default Run the program by clicking the run button 5 As soon as the run button is pressed the status indicator 6 will turn red indicating that the FFT PSD analysis is running Indicator 7 will disp
52. e Supports the AASHTO Standard Specification for Highway Bridges Sixteenth Edition 3 e Supports various loading conditions e Graphic diagrams e Print Save results Sensor Field Component Data Acquisition Field Monitoring Software e Data Collection and Thresholds Processing e Overloaded e Vehicle Impact Structural Analysis Software User Inputs e Bridge Geometry i Communication System Remote Access Received Data Archive End Users i Report Generation i Reduced Data Archive Figure 2 1 Overall schematic of SHM system BEC Analysis was designed to be used specifically for analyzing two dimensional girder bridges subjected to moving loads The structure to be analyzed is idealized to a mathematical model that consists of a member or a series of members In this software member ends are referred to as nodes or joints Properties are assigned to each joint and member to simulate the real structure Member simulations are accomplished by inputting material properties section properties and member definitions within each span Boundary conditions are simulated by assigning restraint conditions to nodes Loads are simulated by combinations of concentrated loads that represent vehicle axles and by uniformly distributed loads plus concentrated load s that represents truck train loadings The commonly used two dimensional stiffness matrix method was used as the computational backbone in BEC Analysis
53. file input When Indicator completed a total number of columns that represents the total number of sensors available will be displayed 8 Select Sensor Control Allows users to select with mouse click a sensor for displaying a PSD plot If selected it will be highlighted in blue 9 Selected Sensor Displays a selected sensor Indicator 10 FFT PSD Plot Indicator Displays FFT PSD plot for the selected sensor 11 Strain History Tab Contains controls and indicators used for displaying Control strain history 12 Chebyshev Filter Allows users to enter parameters that will be used in Parameters Control filtering 13 Event Detection Plus and minus event detection thresholds within which B 17 Threshold Control no peak or event will be detected Microstrain 14 Plot Strain History When pressed strain history will be displayed in graph Control indicator 16 for a selected sensor 15 Strain History for Displays a selected sensor Selected Sensor Control 16 Strain History Plot Provides the status of FFT PSD analysis and or strain Progress Indicator history plot progress If being processed In Progress Wait is shown and turns red Upon completion of FFT PSD analysis and or the strain history plot Ready Now enter parameters and click Plot Strain History is shown and turns bright green 17 Graph Indicator Displays strain history in microstrain for a selected sensor 18 Sa
54. frequency can be determined Once the FFT PSD analysis is completed and the desired cutoff frequency has been determined the second task can be performed to establish the appropriate filter parameters and to see if events peaks are properly identified The following steps are required to perform this task 48 13 Perform the step 7 through step v but this time select a data file that contains traffic plus noise induced strain 14 Select a sensor with a mouse click within control 78 and move to the Strain History tab 11 15 Enter three filter parameters 12 that will be applied to the selected strain data cutoff frequency Hz ripple dB and filter order 16 a The cutoff frequency is determined by investigating dominant frequencies of traffic plus and noise induced and noise alone induced b A ripple of 0 0435 dB which is equivalent to 0 5 passband allowable error is set as a default as it is often a good choice for digital filters 4 The 0 5 passband allowable error was converted to 0 0435 ripple in dB as follows Oo __ 0 0 0435 dB 20 1 0 5 100 The order of a Chebyshev filter is equal to the number of poles in the transfer function of the filter In general a filter is considered to work better with more poles However this may not be always true Therefore several attempts trial and error may be necessary to determine the appropriate filter order The default is set as 274 or
55. front panel B4 4 0815 shown in Fig B 4 L li lii As soon as 4 MainDAQ815 EXE is installed as a service program it will be automatically initialized Given that the data acquisition was successfully initialized as depicted in Fig D 4 the Acquisition Status control 1 will display a green check mark in the status check box and no error message will appear in the source dialog box While the program is running the following information will be displayed on the control panel of the program shown in Fig D 4 Real time raw data for each sensor in the graph indicator 72 The Time indicator 3 displays information on o time at which data acquisition was initialized o current time o count of elapsed hour day week month and year which also indicates the number of data files created and available for report generation Network status 74 One of the following situations will occur o The check mark on the status check box is green and no error message appears on the message box This indicates that the network connection is established and alarm messages and data files created by the program can be sent via email to the recipients specified during input information setting It should be noted that even when the status indicates no error information may not be sent to the recipients due to a security settings Typically used virus scan software is designed to block access from any unknown programs
56. h w password a password and press enter or dick on the OK button Is command clears the password protection message box wil prompt vou to enter the current password Type the current password and press enter or click on the OK button 4 10 Software StrainBoclo6 16 User s Manual C 26 Calibration Parameters Tab Selected mta 2221 Ciba Sron Gage Shut Aa os 0 4 Yer los CE Mew Plate ti Leib Yer Syan Gage Shu FI li os Yer Wes Calend f es enables selected channel to calibrated with the calibrate enabled channels option No prevents the channel from beng caibeated AL other columns for that channel wil be disebiedif no is selected Tha channel still be turned on Wave View Sensor Type Provides a a mess I selecting the De n6 type Choces ere full bridge quarter bridge This option is only aveilabte for strain gage sensor in program The bridge type for any sensor be changed from Sensor Configuration window Bridge Type Calibration Method Allors the celibration method to be selected Possite selections indicated in the figure to the right These calibration methods are explained later document Ee monec Calibration Date Displays the time date that the channel was cabested If the channel has nor been calibrated Not Calibrated appears in the
57. h Gt PIC shape C Rectangular H3 W3 Cancel Click to Compute Properties OK Non Composite Composite N Composite 3N Nt o 2674731183 ft Yt 28223650032 ft Nt o 4948776277 ft GD bee 2909361570 3 4393120514 4 27642813470 Stop 1 7410178762 3 Stop 45986221568 3 Stop 2 5580107050 1355473023 Sbot fi 3603383036 Sbot 12402820148 a Section properties for Define option Figure 2 6 Section Properties window 12 Section Properties C Non Composite Composite Standard Steel Deck E deck 3640 H fio W a E elastic modulus ksi H height inches SW width inches W Shape ef C SShape M Shape C HPShape Channel MC Channel Beam Information Y bottom 20 04 i Area 341 i Depth 40 08 i 251 00 m Sensor Location inches 25 Gt Gt distance from top of beam Gb distance from bottom of beam Gb Non Composite 12104552469 Stop 08524332725 Sbot 08524332725 f 3 Yt fi 6700000000 ft Composite N Yt 2 4845090592 ft Ixc 53453148049 4 Stop 38734103633 3 Sbot 1 0495884432 3 Composite 3N 2 0370083250 ft Ixc 1 7189707933 4 Stop 16324638021 1 3 Sbot 09619265726 3
58. histograms for a typical weekday and weekend day it is obvious that the traffic volume is consistently higher during the daytime than nighttime o The weekday hourly event histogram shows high traffic volume during the evening commute time 5 to 7 PM o The weekend day hourly event histogram shows a bell shaped distribution where the traffic volume is the highest in the afternoon e The traffic volume in a typical weekday is higher than that of a weekend day In all event histograms there are dominant bins with high concentration of identified events e It is expected that if the structural response of the bridge changes due to deterioration and or damage with no significant change in traffic patterns the dominant bins in the 89 event histogram plot will be distributed across several bins and or shifted Table 3 4 Overall summary of 30 day monitoring Sensor ED Eyen Average ue Slope Change 1 221 165 10 0 2 78 12 0 3 91 13 0 4 221 174 10 0 5 219 156 10 0 6 103 10 0 7 116 9 0 8 219 167 10 0 Table 3 5 Statistical Trends daily maximum average in microstrain Sensorl Sensor2 Sensor3 Sensor4 Sensors Sensorb Sensor7 Sensors Day 0 105 11 51 13 47 11 110 12 93 11 80 11 68 11 106 11 Day 1 102 11 41 12 46 13 111 11 99 11 76 11 71 11 105 10 Day 2 105 10 47 11 64 13 131 10 95 9 77 10 104 10 122 10 Day 3 102 9 41 12 47 13 111 9 91 9 74 0 68 8 93 9 Day 4 97 8 42 10 43 10 99 8 89 8 65 7 67 7 93 8 Day 5 105 10 37
59. jumpers must be removed if CN 115 1 or a WBK16 LC option will be used for configuring a channel Jumpers Installing a CN 115 1 CN 154 instsmeg stalling CN 115 Note 8 GALE A or Strarieookjumpers must be WEK1E LC StrerrBook jumpers must be Installed tor CN 115 CN 115 1 Note A for CN 1 15 1 end Wer Le g 116 15 a removable plug Jumpers in adaptor that can be pre 115 4 is a removable plug emere configured for vericus options It differs from tha n boerd that can be pre CN 115 1 only in form factor configured for various bridge options Il differs from the CN 115 ory m form factor WBKT1SILC be used for virtually all single value shurt Installing CN 189 Note C CA 189 is an external temna ophon It can ba used in conjunction w h Bndge Configurations CN 189 calibration requirements some Nota C CN 115 oc CN 115 1 of which not possible wth the ternal FET enalng switch used done without either provisions in the stendard Wourating channel configurations different plug in options instated in the default position When installing a plug in device be careful to avoid bending the pins and ensure that the option is correctly oriented Information for these options can be found using the reference notes below Nate The Note A region represents CN 115 1 or a WBKL LC option plugge
60. low cost SHM system is suitable for implementation of typical girder bridges Excluding the communication and power equipments and R amp D costs the system can be implemented at the cost of 8 000 to 15 000 depending on the number of sensors used e The field monitoring software was developed such that it can handle up to sixteen channels one eight channel StrainBook 616 plus one WBK 16 eight channel expansion module Although the WBK16 was not included in the SHM system its usage was tested during development The installation of the strain gages and laying out the cables required no training special equipment other than safety and normal access equipment Although the time required for sensor installation was only around 30 minutes per gage including surface preparation securing the sensor cable required more time and was relatively labor intensive A two man crew was used to install the strain gages and to secure the cables over a two day period e Based upon comparisons with commercial analysis software the live load structural analysis software BEC Analysis has been proven to be accurate e During a little over thirty days of monitoring period the SHM system has performed as expected and has proven to be capable of continuously and autonomously monitoring the overall performance of the US30 bridge e The SHM system has been proven to be a stand alone autonomous system capable of processing and evaluating the continuously col
61. n Compose TT i w Gene ricev ede Sie Eos Seem Dept f Bears Yemen Iza Gr drance ons of baare Glencoe Pon beaten of bear d Section properties for AASHTO P C option Figure A 4 continued For non prismatic members check to see if the desired section properties moment of inertia in 13 section modulus in 14 and 15 are specified for each segment Different values can be manually entered if needed For non prismatic members enter the length of each section 16 in a manner that corresponds to the figure displayed in 17 This step can be skipped if prismatic option is selected in step vi or in 7 A 10 xiv Click Next 4 to move on If the bridge is composed of more than one span repeat the steps v through xiv until all information for each span is specified xv Select a load option 40 41 or 42 that will be applied to the bridge Fig 5 Figure A 5 Load window For the Iowa Legal Loads HS 20 option 40 choose a live load in the Iowa Legal Loads HS 20 frame 46 The axle weight and configuration displayed in 49 50 and 51 will change depending on a type selected here e For the Truck Train option 41 enter the magnitude of uniformly distributed load in 43 and select a span or spans 45 in which the uniformly distributed load will be applied e F
62. of error error red no error green in the status check box 12 Real Time Raw Data Displays real time raw strain data Indicator 13 Elapsed Time Indicator Displays elapsed time since the beginning of the data Minutes acquisition 14 Data Acquisition Since Displays date and time at which data acquisition is Indicator initialized 15 Current Time Indicator Displays current date and time 16 Stop Control When pressed the program will stop Table B 2 Description of selected controls and indicators in 2 FFT PSD Analysis VI Control or Indicator Description 1 Data File Path Control Path to the preliminary data file 2 FFT PSD Analysis Tab Contains controls and indicators used for FFT PSD Control analysis 3 Sampling Rate Control Sampling rate at which strain records are to be collected Hz Note that the sampling rate must be the same with what was used during the preliminary data acquisition 4 Window for FFT PSD Time domain window to be used in FFT PSD analysis Analysis Control 5 Run Button Control When pressed the program will be executed and the FFT PSD analysis for the selected data file will be initialized 6 FFT PSD Analysis Provides the status of FFT PSD analysis progress If Status Indicator being processed it displays In Progress Wait and turns red Upon completion it displays Data ready to plot Now select sensor and turns bright green 7 Data File Progress Displays the progress of data
63. of the development of the field monitoring software Specific components of the field monitoring software and the required initial setup procedures are then described In addition the general procedures involved in running each component of the field monitoring software are also described 2 2 1 General Background and Methodology 2 2 1 1 Identifying Alarm Events An alarm event is determined by examining the peaks in a strain record Alarm events can be generally thought of as either those caused by overloaded traffic referred to as overload and an abnormal rapid change in strain referred to as impact Some of the important terms that will be used as the building blocks in the field monitoring software are defined as follows e Event any peak in a strain record that exceeds a defined event detection threshold e Alarm event overload event and or impact event e Overload event event that exceeds the overload event threshold e Impact event event that that exceeds the impact event threshold In general two steps are involved in the processing of the collected data identification of events and examination of each event to see if it exceeds the predefined thresholds First any peak in a measured strain record that exceeds the event detection threshold will be identified as an event Once the event is detected the software examines its magnitude in strain and the slope of the strain record that
64. power on the WBK expansion modules if applicable Second power on the StrainBook 616 An exception to this power up scheme ls to power on the entire system at once What you will need or more 10 to 30 VDC power supplies with a male DINS connector The number of supplies depends on the devices in your acquisition system Note The switching mode power supply that is commonly used with these systems has an input range of 100 VAC to 240 VAC at 50 Hz to 60 Hz The power supply s output to the device is typically 15 VDC 3 33 amps via a DINS connector It is likely that you will use TR 40U AC power adapter with your StrainBook 616 and a separate TR 40U for cach WEK expansion module if applicable Note Various AC adapter models support power grids of USA Europe Japan and Asia 545 Setup and Connecting to Ethemet 009616 User s Manual C 7 How to make the connection 1 Using the unit s power switch tum the StrainBook 616 OFF The switch will be in the O position and the Power LED will be unlit 2 Connectthe DINS end of the adapter s cable to the Power Input connector on the StrainBook 616 3 Connect the adapter s plug to a standard AC outlet 4 If your adapter has a power switch position it to ON 5 Tum ON the StrainBook 616 by placing the power switch to the 1 position The Power LED will light up STEP 5 Configure the Computer s Network Settings Applies to
65. sent to the recipients due to a security settings Typically used virus scan software is designed to block access from any unknown programs 52 Therefore users need to make appropriate changes on the security settings so that the execution program 4 MainDAQ 815 VI is unblocked Since the security settings may vary depending on Windows types 2000 XP NT etc and virus scan software used users may need to consult with a system analyst to resolve this o The check mark on the status check box turns red and a message appears on the message box along with an error code This indicates that the network connection is either unavailable or not established It should be noted that this error will not cause the program to stall or stop other functions except the email will still be functioning The program is programmed such that when an error related to network connection occurs the program will skip that step and carry on other tasks Also note that since all data files created by the program will be saved in 3 Data File Folder in the main directory users can always retrieve the data files manually e Available disc and memory space on the field PC The total used and free available disc and physical memory space of the field PC will be displayed in Bytes in the Disc Memory Space indicator 5 Raw data collection with 4 MainDAQ VI is similar to data collection with 1 Preliminary DAQ VI The only significant difference i
66. system setup Enter the sample rate 5 at which the data acquisition is to be performed number of samples per second Enter the impact event threshold in control 6 The impact event threshold is a ratio of the absolute difference between the magnitude of an event and that of a peak detection threshold with respect to the time difference between a start index and a peak index in a strain record a single event or traffic response The impact event threshold is used to determine the type of the alarm event overload or impact both of which exceed the overload event threshold specified in control 8 Enter the plus and minus event detection thresholds 7 that will be applied to the collected strain data In the Overload Event Threshold control 8 enter the overload event threshold for each sensor that was determined from the structural analysis software BEC Analysis Also with a mouse click select LED options for each sensor to which the overload event threshold will be applied If set to true bright green any overload event an event that exceeds the specified overload event threshold for the selected sensor will be recorded and temporarily stored within 4 MainDAQ VI Select the type of data files with a mouse click 79 to be sent via email LED options Given that the internet connection is available if users desire to receive monthly data files only for example the LED option for Monthly Data must be selected bright gr
67. that were used in BEC Analysis were also included in the analyses with STAAD Pro Once the model bridge was constructed with the required input parameters specified the analyses were performed for each Iowa legal truck and results were compared with those generated by BEC Analysis Typical results obtained by running BEC Analysis and those by STAAD Pro are shown in Figure 3 7 In general both analyses produced results with an excellent agreement In all cases the discrepancies in the results generated by BEC Analysis and STAAD Pro were less than 196 thereby validating the accuracy of BEC Analysis 75 2000 BEC Analysis STAAD West Pier 1500 _ 1000 o 5 a 500 o gt 0 50 400 500 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2000 BEC Analysis STAAD West Pier 1500 _ 1000 o 0 o gt 0 50 100 150 200 250 300 350 400 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure 3 7 Analytical moments due to Iowa legal truck Type 3 at the sensor locations with respect to the first axle position 76 3 4 Field Monitoring Software Demonstration This section summarizes how the field monitoring software was specifically set up and used for the US 30 bridge Additionally sample evaluation reports for the US 30 br
68. the actual configuration in use Once the network is fully configured most bridge configurations and resistances can be accommodated without re opening the box The shunt resistors allow each bridge to be put into a known imbalance condition setting or verifying channel calibration Shunt calibration allows a full scale gain to be set without physically loading the bridge Page 6 12 discusses a DB9 Adapter option that provides a means of easily setting up a bridge configuration The following board lay cut shows locations of components referenced to in this chapter The jumper positions are default locations Information regarding the CN 115 header and associated jumpers follows StrainBoow 616 Users Manual 928494 Bridge Configarasons 6 1 C 15 StrainBook s upper circuit board sce preceding figure 15 used to Customize low pass filter frequencies using resistor networks Install Bridge completion resistors Install Shunt calibration resistors A fan draws alr through the unit and exhausts it through the side To maintain sufficient cooling it is important to keep the fan and vents free of obstruction CN 115 Headers Associated Jumpers and Plug In Options 32 Each channel hax CN 115 2x8 resistor socket header and two associated jumpers JP101 and JP102 located on the StramBook s main board The jumpers associated with a given channel rust be installed if a CN 115 will be used for that channel The associated
69. was generated by accessing thirty daily files with 8 Create Report From Multiple Files Only some portions contained in the evaluation reports are summarized and displayed in Tables 3 4 through 3 6 and Figure 3 12 while an example of a complete evaluation report generated by 8 Create Report From Multiple Files VI is provided in Appendix F Each data point in any of the event history plot in Figure 3 12 represents an event identified by the data processing algorithm Along with the maximum daily event and average event a linear best fit trend line for each sensor is given In general a sloping line with time is an indication in a change in bridge behavior condition After reviewing the evaluation report several observations and interpretations were made for overall bridge performance during the monitored period as follows No alarm event had occurred for the monitored period The field monitoring software was programmed to list those events if any that exceed the overload event thresholds for each sensor and as can be seen in Tables 3 4 and 3 5 as well as in Figure 3 12 no identified events exceeded the overload event thresholds that were set Therefore no alarm event is listed in the evaluation report see Appendix F e The magnitudes of the daily maximum events as presented in Table 3 5 and Figure 3 12 fluctuates from day to day It should be noted however that the absolute maximums do not necessarily represent the gradual
70. will result in autonomously creating an Old Data File Folder to which previously archived data files will be moved Meanwhile newly collected data will be saved in 3 Data File Folder a Illustration of Main Data Acquisition tab Figure B 4 Screen shots of 4 MainDAQ815 VI front panel B 10 LAA oo o 100 o 100 b Illustration of Input Information tab Figure B 4 Screen shots of 4 MainDAQ 815 VI front panel continued B5 5 View Strain History VI shown in Fig B5 liii liv lv lvi lvii Select the data file 1 that contains collected strain records Set the path 2 to the filter parameters file that contains the event detection thresholds and filter parameters that were previously established Enter the sample rate 3 that was used during data acquisition Press the Plot Strain History control button 4 to execute the program When this button is pressed the status indicator 5 will turn red indicating that the operation is in progress Upon completion the indicator will turn bright green and the strain history for each sensor will be displayed on the graph indicator 6 The strain history for each sensor can be accessed by selecting the tabs designated for each sensor Stop the program by pressing STOP button control 7 B 11 Figure B 5 Screen shot of 5 View Strain History VI front panel B6 6 View Hourly File VI shown in Fig B 6 lviii
71. 10a while it represents the first axle positions in the moment and strain vs truck position analysis results as shown in Figure 2 10b Also note that in Figure 2 10a the maximum results are displayed separately for each span These numerical data can also be saved to a text file This can be accomplished by pressing the Save to a File command button 76 When pressed the user will be prompted to designate a file path to which the displayed data will be written and saved 27 2 1 2 8 Plot Window Options are available which allow the user to obtain plots of the noment and strain vs truck position diagrams After reviewing and or saving the data a plot can then be generated When the Plot Data command button 77 is pressed the program will move to the Plot window 78 where the moment and strain vs truck position diagrams will be graphically displayed in the plot display box 80 as illustrated in Figure 2 11 2 2 Field Monitoring Software The field monitoring software was developed to function with IOtech instrumentation hardware which will be discussed subsequently The software was designed to collect process and evaluate the measured bridge response Its use will allow bridge owners to quantitatively monitor a bridge for potential cause of damage as well as gradual changes in behavior The following gives general background information and briefly describes the methodology followed during portions
72. 2 More than one channel can be selected by Ctrl Mouse click e Configure each channel 3 based on the type of strain sensor and its setting used e Enter the device name in control 4 The device name used here must match 50 what was used during the hardware system setup Provide the sample rate 5 at which the data acquisition is to be performed number of samples per second Enter the impact event threshold in control 6 The impact event threshold is a ratio of the absolute difference between the magnitude of the event and that of the event detection threshold with respect to the time difference between a start index and a peak index in a strain record a single event or traffic response The impact event threshold is used to determine if the identified event is an impact event Enter the plus and minus event detection thresholds 77 that will be applied to the collected strain data In the Overload event threshold control 8 enter the overload event threshold for each sensor that was determined from the structural analysis software BEC Analysis or other means Also with a mouse click select LED options for each sensor to which the overload event threshold will be applied If set to true bright green any overload event an event that exceeds the specified overload event threshold for the selected sensor will be recorded and temporarily stored within 4 MainDAQ VI Select the type of data files with a mou
73. 28 29 30 Day d 30 day daily statistical trends for Sensor 2 Figure 3 12 continued 23 Microstrain 10000 15000 20000 25000 30000 35000 40000 45000 50000 Event Counts e 30 day event history for Sensor 3 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Day f 30 day daily statistical trends for Sensor 3 Figure 3 12 continued wie a ceo 94 Microstrain Microstrain 206 Overload event threshold 180 Event 160 T T T T T T T 0 20000 40000 60000 80000 100000 120000 140000 160000 180000 200000 220000 240000 260000 280000 Event Counts g 30 day event history for Sensor 4 Overload event threshold Daily Maximum Daily Average Daily Average Fit EEE TEE grr red dup per BT qup E T lt T T T T T T T T T T T T T T T T T T 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Day h 30 day daily statistical trends for Sensor 4 We 4 D u Figure 3 12 continued 95 Microstrain Microstrain 5 Dverload event threshold vent 8 Event Counts 1 30 day event history for Sensor 5 240 o age py a e TTT TTS ER ET EE EEE EES EEE EES EEE SE UU Overload event threshold Daily Maximum 180 Daily Average Daily Average Fit E M T t
74. 3 07 S TEM DEMONSTRATION Saeed pr 63 31 Bridge Desctiptign cu see tico tee a e ali 63 32 Hardware Components Installation esses 67 3 3 Determination of Overload Event Threshold sse 71 3 4 Field Monitoring Software Demonstration sess 77 SUMMARY AND CONCLUSIONS ci state AAAS 102 JL 102 2 2 6 ohne coc suse ctetu 104 S REFERENCES ha e A M E D M e ede 105 APPENDIX A 1 APPENDIX BS as dM 1 SSSA C 1 PRP PEIN DD TT T H D 1 APPENDIX B 5 lt 66 E 1 APPENDIX F ehe Ue Poorer Ve 1 LIST OF FIGURES Figure 2 1 Overall schematic of SHM SySICH ode ehe nice Dl obi 4 Figure 2 2 General flowchart illustrating the overall operation of BEC Analysis 8 Figure 2 3 Analysis title screen ia queue eerta sevo desert eta ue ed a e OR RT RES tu 9 Figure 2 4 General information options 10 Figure 2 5 Span Description WindOW coste eis eese inerte o Sa UY denn Ex e 11 Figure 2 6 Section Properties windOW i e etes onset etern
75. 3 1 and 3 2 the least absolute maximum strains were resulted from the H 20 truck for both spans and therefore 219 microstrain and 221 microstrain were selected as the overload event thresholds for the plate girders in the west end span and in the center span respectively 73 Table 3 1 Summary of maximum moments ft kips and strains microstrain and corresponding first axle positions b1 ft for Sensors 5 and 8 Load Type Moment bl ft Strain b1 ft Iowa Legal Truck Type3 1384 64 250 64 Iowa Legal Truck Type4 1538 60 277 60 Iowa Legal Truck Type3S2A 1674 63 302 63 Iowa Legal Truck Type3S2B 1596 63 288 63 Iowa Legal Truck Type3 3 1806 68 326 68 Iowa Legal Truck Type3S3 1724 84 311 84 H 20 Truck 2 axles 1216 63 219 63 HS 20 Truck 3 axles 14 ft 1929 63 348 63 HS 20 Truck 3 axles 15 ft 1907 63 344 63 HS 20 Truck 3 axles 20 ft 1798 63 324 63 HS 20 Truck 3 axles 25 ft 1692 63 305 63 HS 20 Truck 3 axles 30 ft 1589 63 287 63 Truck train or Lane loading 1637 49 295 49 Table 3 2 Summary of maximum moments ft kips and strains microstrain and corresponding first axle positions b1 ft for Sensors 1 and 4 Load Type Moment bl ft Strain b1 ft Iowa Legal Truck Type3 1404 178 253 178 Iowa Legal Truck Type4 1556 178 281 178 Iowa Legal Truck Type3S2A 1716 177 310 177 Iowa Legal Truck Type3S2B 1688 177 305 177 Iowa Legal Truck Type3 3 1859 192 335 192 Iowa Leg
76. 4 2006 4 37 46 PM 4 d rss mem vu Soda Mn m Ad wi ls t eR orta ed T oe Ulead by Issa Jessy Deae Sener 7 1 Monitoring Period 11 14 2006 3 00 18 PM 12 14 2006 4 37 46 PM Create by lira osos ones by Dee center 8 Monitoring Period 11 14 2006 3 00 18 12 14 2006 4 37 46 PM Repo martin size 11214200 2 00 16 P Orde by lira osos June s by Deide center
77. 6 Software StrainBook 616 User s Manual C 29 C3a Sensor Calibration Example o Sensor type Hitec Product weldable quarter bridge strain gage o Gage Factor 2 0 o Number of sensors 10 strain gages 8 channels for StrainBook 616 0 17 to 0 8 2 additional channels for WBK16 expansion module 1 17 and 1 2 o Bridge completion resistor BCR 350 2 o Shunt calibration resistor 57933 This is an example of calibrating 10 quarter bridge strain gages and the required procedures illustrated in Figs C 1 and C 2 are as follows Ixxi Turn on the StrainBook 616 and 16 expansion module note the module first and then the StrainBook 616 Once the equipment is on start WaveView software Ixxii Go to File and select New Under On Off column 1 select channels to be activated 1 switch to On Ixxiv Click Hide Inactive Channel Rows 2 to have only activated channels displayed lxxv Select mV 3 30 3 to 30 3 4 lt 5 5 and 1 4 Bridge 6 for all activated channels as illustrated in Fig C 1 Ixxvi Click Calibration 7 which will open up a window StrainBook616 WBK 16 Sensor Configuration shown in Fig C 2 Ixxvii Select the channels to be calibrated 1 switch to Yes in the Cal column 8 and configure each sensor as follows Sensor Type 9 Strain Gage Bridge Type 10 Bridge Calibration M
78. 6 View Hourly File 1 Table B 7 Description of selected controls and indicators in 7 Create Report From Single File VI and 8 Create Report From Multiple Files VI ix ACKNOWLEDGMENTS The investigation presented in this report was conducted by the Bridge Engineering Center at Iowa State University The research was sponsored by the Iowa Department of Transportation Highway Division and the Iowa Highway Research Board Bruce Brakke of the Iowa Department of Transportation is acknowledged for his support of the project and for his technical input Several other Office of Bridges and Structures personnel at the Iowa Department of Transportation provided input and support during the project and are also acknowledged particularly Ahmad Abu Hawash and Norm McDonald xi EXECUTIVE SUMMARY This report is divided into two volumes Volume I summarizes a structural health monitoring SHM system that was developed for the Iowa DOT to remotely and continuously monitor fatigue critical bridges FCB to aid in the detection of crack formation The developed FCB SHM system enables bridge owners to remotely monitor FCB for gradual or sudden damage formation The SHM system utilizes fiber bragg grating FBG fiber optic sensors FOSs to measure strains at critical locations The strain based SHM system is trained with measured performance data to identify typical bridge response when subjected to ambient traffic loads and that knowl
79. 7 7 77 J 7 2 7 m am up up ep 7 Lp AV AV AY rrrrr rrr rrr rr rrr rrr rrr tt Per rrr rT ret gt 4 0 30 60 90 120 150 180 4 Mid Microstrain b Hourly event histogram for Dec 3 Sunday 2006 Figure 3 13 Hourly event histograms of typical weekday and weekend day for Sensor 4 bin width 5 microstrain night 100 12000 100004 aad cccccccadxccecscacoccc 80004 D 2 gt 6000 Frequency 4000 4 20004 0 4 2 0 30 60 90 120 150 180 a Daily event histograms Nov 14 3 pm through Dec 14 3 pm 2006 60000 50000 40000 30000 Frequency 20000 10000 1 em 9228 IT CC CC J o A II NII IND INDIA III DIDI AN IAI AE 2 0 gt Ld Tegel spo Eod db d bed de dede 4o TI TI TT Week 0 30 60 90 120 150 180 Microstrain b Weekly event histogram Nov 14 3 pm through Dec 12 3 pm 2006 Figure 3 14 Daily and weekly event histograms for Sensor 4 bin width 5 microstrain 101 4 SUMMARY AND CONCLUSIONS 4 1 Summary The primary objective of this project was to develop a continuous SHM system that can provide bridge owners with tools to better manage their bridge assets T
80. 8 Moments and strain due to HS 20 truck 3 axles 14 ft at the sensor locations with respect to the first axle position E 9 2000 Moment ft kips Strain microstrain West Pier 1900 4 East Pier 1000 4 2 9 500 c o 0 0 50 350 400 500 4 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2000 Moment ft kips Strain microstrain West Pier 1500 4 1000 5 9 500 gt 0 0 400 500 4 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 9 Moments and strain due to HS 20 truck 3 axles 15 ft at the sensor locations with respect to the first axle position E 10 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 0 5 9 500 c 0 i 50 10 150 200 2 300 350 400 500 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2 poy Moment ft kips Strain microstrain West Pier East Pier c gt 300 350 400 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 10 Moments and strain due to HS 20 truck 3 axles 20 ft at the sensor locations with respect to the first axle position 2000 Moment ft kips
81. 81 19 63 26 60 22 09 30 10 24 82 33 77 27 84 37 80 3116 4218 3477 46 92 38 68 52 01 42 88 57 45 47 35 63 22 52 11 69 33 57 15 75 77 62 46 Save to a File Plot Data Back Exit b When At a designated location option is selected CO CO Co Figure 2 10 continued 22 inches Top 175 Print Plot LN 6 Moment amp Strain Envelo Momaert JMoment JStan Sain Moment koe or Stain Distance 5 from Left Exterior Support a When In each span option is selected Figure 2 11 Plot window 23 165 Margin inches Let 075 Moment and Strain vs Truck Position Moment Stain 200 300 400 500 Strain First Axle Postion ft from Left Exterior Support b When At a designated location option is selected Figure 2 11 continued 24 2 1 2 3 Section Properties Window The Section Properties window 19 illustrated in Figure 2 6 will only be called when the Calculator command 12 is pressed In this window geometric section properties for general section types user defined standard steel Iowa P C and AASHTO P C can be computed Frames 20 and 21 allow the user to generate section properties for either composite or non composite sections Composite action calculations are engaged when the
82. Book or WBK16 channel The gage will be used in an environment were the expected range of measurement is limited to 200 to 1000 ye This gage in its quiescent state has a 500 we load A 349 650 Ohm precision resistor is available that will be mounted on the plug in header in Shunt location R B Instructions for installing shunt resistors are provided elsewhere in the document In this example the user would enter the following values in the Calibration Parameters spreadsheet Cal Method Shunt R B Excitation 2V Gage Factor 2 Shunt Ohms 349 650 Bridge Ohms 350 Max Load 1000 Quiescent Load 500 Point 1 Units 200 The accuracy of Shunt Calibration ss directly related to the tolerances of the Shunt resistor Gage s and Bridge Completion resistors used in the circuit In the event that a precision shunt resistor is unavailable Wave View provides an alternate way of calculating Shunt calibration constants This method is as follows a Install an appropriate non precision shunt resistor of a value that creates the degree of bridge imbalance desired 5 Press and hold the lt Alt gt key on the computer s keyboard then start the calibration process Once the calibration process has started you release the lt gt key This alternate Shunt Calibration method calculates the shunted load value from shunted and un shunted bridge voltage measurements and then performs the equivalent of a 2 Point Manual calibration 41
83. C Analysis are the same to the routine stiffness method except that the member stiffness matrix and the fixed end moments are specific functions of the variation in the member cross section BEC Analysis runs on a Windows platform personal computer and consists of three modules pre processor analysis and post processor Each module was respectively developed to perform a certain task such as model generation analysis and result viewing These three modules can be further categorized into six groups 1 Bridge Information windows 2 Span Description windows 3 Load window 4 Run Analysis window 5 Print View Plot windows The pre processor groups 1 2 and 3 are used for data input modeling and on screen graphic display of the data input and editing is completed with the aid of windows screens each of which contains controls and indicators The analysis module 4 performs a live load analysis of a model bridge and is activated when the program is executed The last module postprocessor 5 was designed for reviewing analysis results Overall BEC Analysis is capable of analyzing a bridge beam or girder with various boundary conditions and member geometries It also allows the structural response to be analyzed under various loading conditions One unique feature of BEC Analysis is that it allows users to easily determine maximum results maximum moment and strain at any location along the length of a model bridge subjected to moving loads
84. Evaluation of Steel Bridges Volume Il Structural Health Monitoring System for Secondary Road Bridges BRIDGE Final Report December 2007 Sponsored by the Iowa Department of Transportation Project 03 135 and the Iowa Highway Research Board Project TR 493 Center for Transportation Research and Education IOWA STATE UNIVERSITY Iowa State University s Center for Transportation Research and Education is the umbrella organization for the following centers and programs Bridge Engineering Center Center for Weather Impacts on Mobility and Safety Construction Management amp Technology Iowa Local Technical Assistance Program Iowa Traffic Safety Data Service Midwest Transportation Consortium National Concrete Pavement Technology Center Partnership for Geotechnical Advancement Roadway Infrastructure Management and Operations Systems Statewide Urban Design and Specifications Traffic Safety and Operations About the Bridge Engineering Center The mission of the Bridge Engineering Center is to conduct research on bridge technologies to help bridge designers owners design build and maintain long lasting bridges Disclaimer Notice The contents of this report reflect the views of the authors who are responsible for the facts and the accuracy of the information presented herein The opinions findings and conclusions expressed in this publication are those of the authors and not necessarily thos
85. Instruments Corporation 231 pp Austin TX 2004 105 APPENDIX A 1 Description on controls indicators and command buttons 109 A2 Principle Procedures in Running BEC Analysis 1 14 4 e eee eee eee ee nece 115 AT Descriptions on controls and indicators used in BEC Analysis 1 Bridge Information Window Contains the BEC Analysis title screen and General Information frame 2 Number of Spans Control Total number of bridge spans The number entered here will dictate the number of Span Description windows 5 into which information for each span will be entered 73 Boundary Condition Frame Describes how a model bridge is supported Three options are available for exterior supports fixed pin roller and rotational spring Note that interior supports are assigned to be rollers with 10096 continuity over the support 4 Next Command Moves to the next window 5 Span Description Window Allows geometry member type and material and section properties for each member to be defined Up to ten Span Description windows will appear one by one depending upon the input given in 2 6 Span Length Control Span length 7 Member Selection Frame Two options are available e Prismatic member member size and section properties are constant along the span If selected controls 8 and 16 will be disabled Non prismatic memb
86. Last 1 days to present Figure 2 23 Data file selection option for 8 Create Report From Multiple Files VI 58 b Statistical Trends hourly trend for 24 hours c Statistical Trends daily trend for 7 days Figure 2 24 Examples of event histogram and statistical trends 29 2 3 Hardware System This section describes the hardware components of relevance to the developed system The hardware system generally consists of sensors the data acquisition instrument and optionally a communication system 2 3 1 Sensor Among the numerous types of sensors that can be used in SHM strain sensors offer a convenient and well understood method to instrument a bridge Strain sensors measure expansion and contraction in the substrate material induced by mechanical stress or thermal effects Three types of conventional strain sensors are commonly used strain transducers weldable strain gages and bondable foil strain gages The selection of strain sensor typically depends on a number of factors cost durability and temperature sensitivity Although virtually any strain sensor could be used with the developed system weldable strain gages from Hitec Products Inc were selected to be the recommended sensor Hitec Products manufactures weldable strain gages that are precision foil gages bonded to a stainless steel shim prewired and waterproofed These strain gages are hermetically sealed and are designed to wi
87. Menus Control functions in the sensor configuration window are available through the pull down menus or the toolbar For descriptions of button functions see the related menu selections Note thal some menu selections have no corresponding button Sensor Configuration Window Toolbar 1 New Configuration 2 Load an Existing Configuration 3 Save Current Configuration 4 Take a Single Reading 3 Calibrate Enabled Channels 6 Return to WaveView StreinBock 6 16 User s Manual Saofiwere 4 9 25 File The Fije menu provides four functions Set parameters 10 ther default startup setting _ Load a saved sensor calibration config ur to Wave View 7 tho Sensor Confurstionvindow and renum to WaveView Calibration The Calibration menu provides two functions his command allows the user to take snige reading and dispiay the values in the Sensor Configuration window The sensor calibration application provides password protection If you calibrate any StrainBook channels or WBK16 expansion channels and then choose the password protection option WaveView will prevent other users from making changes to your calibration file The Password menu provides three functions Lise thes command to enter prewoushy selected password enabling you to change parameters This commend allows the user to select 4 7 character password A message will prompt you to emer a
88. O 0 mv 30 310 303 No 0 Bypass 10 00 DC 50V 1 4Bridge No Bypassed 0 8 On 0 mv 30 3 10303 D Bypass 10 00 DC 50v 1 4Bridge No Bypassed 1 1 CH09 0 mv 30310303 No 0 Bypass 10 00 DC 50V 1 4Bridge No 11 2 OmV 30310303 0 Bypass 1000DC 507 rere Fie Calibration Password Sensor Configuration 18 Cal Point 1 Load Value D om 288 cell Calibration Parameters Channel Values Exc Gage Sensitivity Shunt Bridge Full Rated Max Appl Quiescent Point Paint Point2 Poir Calibration Date Units Label Sensor Label Volts Factor Resistor Resistor Load Load Tare mv V Ohm Ohm Units Units Units mV Units mV Uni Strain Gage 1 4 Bridge Shunt Rd Mot Calibrated e S N 5 0V 2 000 57983 350 3000 0 0 0 3000 0 Strain Gage 1 4 Bridge Shunt Rd tC ated S N 50v 2 000 57983 350 3000 0 00 3000 0 Strain Gage 1 4 Bridge Shunt Rd ed e CH S N 50v 2 000 57383 350 3000 0 0 0 3000 0 Strain Gage 1 4 Bridge Shunt Rd Mot C ated S N 50v 2 000 57983 350 3000 0 00 3000 0 Strain Gage 1 4 Bridge Shunt Rd No ed ye CHO5 S N 5 0V 2 000 57983 350 3000 0 0 0 3000 0 Strain Gage 1 4 Bridge Shunt Rd 2 CHO06 S N 50v 2 000 57983 350 3000 0 00 3000 0 Strain Gage 1 4 Bridge Shunt Rd Mor 1 ye CHC S N 50v 2 000 57383 350 3000 0 0 0 3000 0 Strain Gage 1 4 Bridge Shunt Rd e CHO8 S N 5 0V 2 000 57983 350 3000 0 0 0 3000 0 Strain Gage
89. Prismatic Non Prismatic Member Member Type Member Cross Section Beam Material C 2 Define 9 Steel 19 3sections 1 to 13 Standard Steel C Concrete C 4sections 1014 C lowaP C B sections 1 1015 AASHTO P C Moment of Inertia ft 4 and ipn Modulus ft 3 for each section E ksi 2 Calculator 3371 51 2205 S10 2905 Section Length ft AIL 15 Calculator 1934 52 1904 S20 1904 AL 5 Calculator 1972 530 1730 530 1730 O Calculator 1577 S4 1406 S40 1406 B 2493 55 2396 S5 2396 Figure 3 Span Description window A 7 e Scenario Fig A 4a when Define option is selected in 9 a b Select an option for the deck to be either composite or non composite with the girder 20 Enter the modulus of elasticity and the thickness and effective width of the deck 21 Select a desired cross section shape among the nine general section types 22 A corresponding figure that contains general information will be displayed in 23 Enter the dimensions 24 for each component Specify where sensors to be placed 1 top and bottom sensor locations 25 for which the corresponding section modulus will be determined Press the Click to Compute Properties 26 to compute the section properties Click either OK 27 to copy the computed section properties into 13 14
90. Sensors 1 and 4 in the center span 1500 4 Moment ft kips Strain microstrain West Pier East Pier c m 0 0 500 4 1000 50 100 150 200 250 300 350 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 13 Moments and strain due to HS 20 truck train lane loading at the sensor locations with respect to the first axle position E 14 APPENDIX F Evaluation Report November 14 2006 December 14 2006 F 1 Monitoring Period 11 14 2008 30018 PM 12 14 2006 4 37 46 Monitoring Summary microstrain _ Created by lows Sate University Bridge Engineering Center 1048 2 Monitoring Period 11 14 2006 3 00 18 PM 12 14 2006 4 37 46 PM Ulead by Lea onmes Deae Len esting Sener Monitoring Period 11 14 2006 3 00 18 PM 12 14 2006 4 37 46 PM Credu by Issa Jessy Deae esting Sener Monitoring Period 11 14 2006 3 00 18 PM 12 14 2006 4 37 46 PM Daily Trends Maximum amp Average Massi am by Sas ES ly Deas Cre Sener 2230 F 5 Monitoring Period 11 14 2008 300 18 PM 12 14 2006 4 37 46 gt 355 qu uu 508 Created by lows Vewversty Bridge Engineering Center F 6 Monitoring Period 11 14 2006 3 00 18 12 1
91. a Span 1 1 Q 3 4 5 65 0 26 0 4 0 b Span 2 1 2 3 26 0 67 6 Span 3 Figure 3 6 Plate girders divided into sections Once all the input parameters were established BEC Analysis was run following the steps described previously and the overload event thresholds at each sensor location were determined In addition the bridge was analyzed with other commercially available software 72 to verify the results generated by BEC Analysis The results generated by BEC Analysis and their verification checks are presented in the subsequent sections 3 3 1 Live Load Analysis with BEC Analysis In this section the live load analysis results generated from running BEC Analysis for the US 30 bridge are presented In each run the bridge was subjected to a moving load that traversed the bridge Various loadings including Iowa legal trucks H 20 HS 20 trucks and truck trains or lane loads were considered and each loading type was analyzed individually The Iowa legal trucks H 20 and HS 20 trucks were simulated with series of concentrated loads while concentrated load s and uniformly distributed loads were used to simulate the truck train or lane loading For the HS 20 truck with 3 axles although the distance between the first two axles remains the same one needs to consider different spacing for the last two axles rear axles spacing as it can vary from 14 to 30 ft as specified in the
92. a preliminary engineering assessment but also with consideration of accessibility To this end four strain gages Sensors 5 though 8 were installed in the positive moment region of the plate girders and stringers in the center span and four sensors Sensors 1 though 4 in the West end span as shown in Figure 3 4 Note that all sensors were installed on the top of the respective member bottom flange Installation of the strain gage began with surface preparation A hand held grinder was used to remove the paint from the steel beams The strain gages were then attached to the steel surface using a portable battery operated low capacity discharge spot welder Since the SHM system is intended for a long term monitoring additional measures were performed to ensure longevity of the strain gages After welding each strain gage was covered with butyl rubber and aluminum foil tape to protect them from surrounding moisture The installation of the strain gages cables required no training or special equipment other than safety and normal access equipment such as harness ladder etc Although the time required for sensor installation was only around 30 minutes per gage including surface preparation securing the sensor cable required notable time and was relatively labor intensive A two man crew was used to install the strain gages and to secure the cables over a two day period 3 2 2 Data Acquisition Processing and Communication System The data acq
93. ain Data Acquisition Reduction and Evaluation After a DAQ Inputs file that contains the input information is created the main data acquisition and processing can be initiated by running 4 MainDAQ VI As soon as 4 MainDAQ VI program is run it checks the data acquisition instrument Given that the data acquisition was successfully initialized as depicted in Figure 2 17 the Acquisition Status control 1 will display a green check mark in the status check box and no error message will appear in the source dialog box While the program is running the following information will be displayed on the control panel of the program shown in Figure 2 17 e Real time raw data for each sensor in the graph indicator 2 e The Time indicator 3 displays information on o time at which data acquisition was initialized o current time and o count of elapsed hour day week month and year which also indicates the number of data files created and available for report generation Network status 4 One of the following situations will occur o check mark on the status check box is green and no error message appears on the message box This indicates that the network connection is established and alarm messages and data files created by the program can be sent via email to the recipients specified during input information setting It should be noted that even when the status indicates no error information may not be
94. ain variable A quarter bridge has 1 strain variable element a half bridge has 2 strain variable elements and a full bridge has 4 strain variable elements Full bridges generally have the highest output and best performance Output signal polarity is determined by whether the strain varinble resistance increases oc decreases with load where it is located in the bridge and how the amplifier inputs connect to it Configuration polarity is not important in StrainBook due to an internal software selected inversion stage This simplifies bridge configuration Each of the 8 input channels has locations for five bridge completion resistors These BCR s are for use with quarter and hal bridze stram gages The resistors make up the fixed values necessary to complete the 4 clement bridge design A full bridge gage requires no intemal completion resistors However the resistors may still be installed for other configurations in use The additional resistoes will be ignored when the software has selected full bridge mode Quarter bridge and half bridge gages require an internal half bridge consisting of header positions Rg and Rh The recommended minimum values 0 1 lt 5 PPM C drift 1 KO and 0 25 watt resisters Lower values will dissipate more power and add heat Values gt 1 will increase the amount of drift and noise The same value half bridge resistors can be used for any resistance strain gage This intemal half bridge will be automat
95. ain vs truck position analysis results generated during the analysis depending on the option selected either 53 or 54 75 Output Data Display Box Displays output data to be saved in a text file 76 Save to a File Command When pressed data displayed in 75 will be saved to a text file 77 Plot Data Command Allows users to plot envelopes or moment and strain vs truck position diagrams generated during the analysis 78 Plot Window Allows users to view and print a plot of envelopes or moment and strain vs truck position diagrams generated during the analysis 79 Print Plot Command When pressed a plot of envelopes or moment and strain vs truck position diagrams will be printed 80 Plot Display Box Displays a plot of envelopes or moment and strain vs truck position diagrams generated during the analysis A2 Principle Procedures in Running BEC Analysis i Press Click to START Fig 1 on the BEC Analysis title screen to initialize the BEC Analysis This will open the General Information frame ii Enter the number of spans by entering the desired number in 2 Fig A 2 Set the boundary conditi or each span in 3 iv Click Next 4 to move to the Span Description window 5 as shown in Fig 3 v Enter the span length in 6 vi Select the member type 7 If the Prismatic Member option is selected in 7 skip step vii If the Non Prismati
96. aining the information processed by the program will be created based upon the options 3 4 and 5 selected 8 Report Generation Provides the progress of displaying the results and Progress Indicator generating reports If in progress Wait is shown and turns red If completed Ready Done is shown and turns bright green 9 Monitoring Since Displays the date and time since the beginning of the Indicator data acquisition 10 Monitoring Period of Displays the monitoring duration in date and time for Selected File Indicator selected file s 11 Alarm Message Displays summarized alarm messages recorded over the Indicator monitoring period displayed in 10 12 Event History Tab Contains graph indicators that display strain history for Control each sensor 13 Event Histogram Tab Contains graph indicators that display event histogram Control for each sensor 14 Statistical Trends Tab Contains graph indicators that display statistical trends Control for each sensor 15 STOP Control When pressed the program will stop 16 Graph Palette Control Changes the scale and the format of the plot while the program is running or stopped B 22 APPENDIX C Setup and Connecting to the Ethernet ccce ee eee eee ee ee ee ee eren 150 System Requirement EXPE leks 150 C1 2 IOtech Software Installation e
97. al Truck Type3S3 1800 198 325 198 20 Truck 2 axles 1228 177 221 177 HS 20 Truck 3 axles 14 ft 1947 177 351 177 HS 20 Truck 3 axles 15 ft 1926 177 348 177 HS 20 Truck 3 axles 20 ft 1825 177 329 177 HS 20 Truck 3 axles 25 ft 1731 318 312 177 HS 20 Truck 3 axles 30 ft 1646 177 297 177 Truck train or Lane loading 1670 163 301 163 3 3 2 BEC Analysis Validation In order to validate the accuracy of BEC Analysis numerous structures were analyzed with BEC Analysis and their results were compared to those generated by hand computations as well as other structural analysis software such as QConBridge and STAAD Pro Only the validation checks performed with STAAD Pro in which the US 30 bridge was used as a model bridge are presented here Using STAAD Pro an analytical model representing the plate girders was constructed with two dimensional beam elements and a pinned support boundary condition assigned at the 74 west pier and roller supports assigned at the east pier and at the both abutments Each span was divided into sections in a manner that was used in BEC Analysis as shown in Figure 3 6 After modeling the bridge moving loads that represent the Iowa legal trucks Types 3 4 352 A 352 B 3 3 and 383 were created and the model bridge was analyzed for each of the Iowa legal trucks An increment of 1 ft was used to dictate the total number of load cases simulating the moving trucks The DF and IM
98. am As soon as the program is executed the status indicator 8 will turn red indicating that the program is in progress Upon completion the indicator will turn bright green and the following results will be generated o results displayed on the front panel for immediate view the time at which the data acquisition was initialized 9 e the monitoring period 10 e alarm messages recorded during the monitoring period 11 e event history event histogram and statistical trends for each sensor 12 13 and 14 respectively see Note 2 below for more detail o Excel Worksheet hard copy and or PDF file depending upon the selected options 3 4 and 5 e Stop the program by pressing STOP control 15 56 Note 1 As can be seen in Figures 2 20 and 2 21 controls and indicators used on the front panels of each program are exactly the same with the exception of the Monitoring Period control 2 7 Create Report From Single File VI is designed to access one data file at a time while 8 Create Report From Multiple Files VI allows users to open multiple files at once Consequently different options in control 2 for selecting data files were utilized For 7 Create Report From Single File VI users can choose a different type daily weekly monthly and yearly of data file from provided tabs where the title of each tab represents a time duration for which one file is created and archived as shown in Figure 2 22 For exampl
99. am is terminated Contained in each file are columns of tab delimited data with each column representing the strain record for one sensor For example if eight sensors are used the data file will contain eight columns of tab delimited data The main goal of acquiring these sample data sets is to collect data to be used for noise reduction by separating traffic induced frequencies from noise induced frequencies To do this properly two steps are required The first step requires the collection of strain data sets a when ambient traffic crosses the bridge and b when no traffic is present on the bridge The second step is described in the following section 2 2 32 Investigation of Frequency Contents and Determination of Filter Parameters Identification of strain due to noise involves comparing noise induced frequency contents with those induced by traffic The data sets obtained from running Preliminary DAQ VI are used to perform a FFT analysis that results in a power spectral density PSD plot for each strain record The FFT PSD analysis allows users to view different frequencies that make up the measured strain By investigating the PSD plots dominant frequencies from ambient traffic and noise can be identified As previously mentioned traffic induced strains in a typical bridge normally have frequency contents that are lower than those of noise With this frequency characteristic therefore one may minimize noise by applying a low pass
100. and indicators Table B 1 Description of selected controls and indicators in J Preliminary DAQ VI Control or Indicator Description 1 Device Name Control Name of a StrainBook 616 assigned during IOtech software installation described elsewhere 2 Sampling Rate Control Sampling rate at which strain records are to be collected Hz number of samples per second 3 StrainBook 616 Channel Channels of StrainBook 616 to be activated When Control selected Ctrl mouse click the indicator turns blue 4 WBK16 Channel Channels of WBK16 expansion module to be activated Control When selected Ctrl mouse click the indicator turns blue 5 Sensor Configuration Parameters that need to be configured for each sensor Controls 6 Calibration File Applied If set to true bright green a selected calibration file is Control LED option applied 7 Calibration File Path Path to calibration file created during calibration process Control see Appendix C 8 Data File Save Path Directory in which raw strain data files are to be saved Control 9 Data File Saved at Time duration for which each raw strain data file is Control Minutes saved 10 Start Control When pressed data acquisition will begin 11 Acquisition Status Error dialog box that displays a numeric error code and a Indicator corresponding error message upon occurrence
101. and strain due to Iowa legal truck Type 3 at the sensor locations with respect to the first axle position E 2 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 1000 5 9 500 i c 1 E o 2 0 50 00 150 200 0 300 350 400 1 500 i 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 1000 9 500 o 0 50 100 150 200 250 300 350 400 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 2 Moments and strain due to Iowa legal truck Type 4 at the sensor locations with respect to the first axle position E 3 2000 Moment ft kips Strain microstrain West Pier 1500 4 East Pier c 5 t o gt 400 500 4 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2 din Moment ft kips Strain microstrain West Pier 1500 1000 B 9 500 gt 0 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 3 Moments and strain due to Iowa legal truck Type 3S2 A at the sensor locations with respect to the first axle position EA
102. ay real time data elapsed time beginning time at which data acquisition is initialized and current time of data acquisition respectively This indicates that the data acquisition instrument was found and that all input parameters are correctly defined o The check mark on the status check box turns red and a message appears on the message box along with an error code This indicates that either the data acquisition instrument was not found or one or more input parameters are missing In order to resolve this error users must check either or both the hardware and IOtech software installation setup or and the input parameters before running the program again e Once the data acquisition is completed click the STOP button 16 This will 46 terminate the program Each saved data file is named with letters and numeric numbers The notation starts with SHM followed by numeric numbers representing the time at which each data file was saved The naming conventions adopted are described as follows SHM YYYY MM DD hhmmss where SHM Structural Health Monitoring YYYY year e MM month e DD day e hh hour of the day e mm minute of the hour e ss seconds within the minute When the elapsed time 13 exceeds the time specified in control 9 the data file will be closed and saved to the directory designated in control 8 Meanwhile new data will be written to a new file This process will be repeated until the progr
103. ble Items gt gt Graph Palette from the shortcut menu The formats used to display event history and event histogram are the same for both programs Also the format used to display statistical trends in 8 Create Report From Multiple Files VI is the same However the format of the graph indicator for displaying statistical trends in 7 Create Report From Single File VI can change depending on the B 14 tabs or pages selected in the Monitoring Period control 2 If users select a monitoring period in the Daily tab the graph indicator will display statistical trends of each hour for 24 hours On the other hand if users choose a monitoring period in Weekly Monthly or Yearly tabs it will display statistical trends of each day for user specified monitoring periods For example if a monitoring period is selected in the Weekly tab on the front panel of 7 Create Report From Single File VI it will access one of the weekly created data files each of which contains collected information for seven days Therefore it will display statistical trends of each day for 7 days 32 02 AM Sensor4 Overload 11 15 2006 8 31 43 PM Sensor4 Overload 100 Mcrostrain Figure B 7 Screen shot of 7 Create Report From Single File VI front panel 4 4 11 16 2006 4 22 44 74 Senior Overbed 100 Figure B 8 Screen shot of 8 Create Report From Multiple Files VI front panel Description on controls
104. c Member option is selected continue on the next step vii Select the number of discrete segments sections to be used to describe the member 8 viii Select a type of member cross sections that will be used in Calculator 12 If section properties of a member are already known and will be entered manually this step can be skipped ix Select a member material Upon selection corresponding values will be specified to 11 x Check to see if the desired modulus of elasticity is displayed in 11 A different value can manually be entered if needed xi This step can be skipped if section properties for each segment are manually entered Otherwise click Calculator 12 A Section Properties window will appear based upon the option 9 selected in step viii Bridge Information BEC ANALYSIS A Live Load Structural Analysis Program for Bridge Structures and Components C Copyright lowa State University Bridge Engineering Center Click to START IOWA STATE UNIVERSITY OF SCIENCE AND TECHNOLOGY BRIDGE Pese Figure A 1 BEC Analysis title screen on Bridge Information window Bridge information Caran inform of pore mpm 18 ptm Border Tag on T ort Fe Ene Sunnet Pv so Fob Figure 2 General information options on Bridge Information window Span Description Span 1 Description Span Length ft Member Selection C
105. ce In this scenario StrainBook 616 is connected directly to an Ethernet jack on a host computer Dedicated Network using a Direct Cable Connection 54 Setup and Connedingto the Ethemot SireirBocko616 Users Manual C 5 Dedicated Network making use of a network hub or switch In this scenario the StrainBook 61 6 connects to the Ethernet through a network hub or switch At least onc computer is also connected to the hub Dedicated Network using a Hub Switch Some network devices such as a wireless access point may act us a DHCP server If this is the case follow the instructions for the LAN with a DHCP server For detailed information consult the documentation that is specific to your network device LAN with a DHCP Server Local Area Network with a Dynamic Host Configuration Protocol server Many corporations use the LAN Server with DHCP arrangement for their networks In this type of setup several computers are typically connected to a network that makes use of a DHCP server In addition StrainBook 616 is connected to the network hub switch LAN with a DHCP Server Using a StrainBook 616 on a typical LAN may affect the speed of the network and intemet data transfer Because of this we recommend adding a network card to the computer and using one of the two dedicated network configurations Contact your network administrator before connecting a StrainBook 616 to a corporate network Users Man
106. contains the event If the event exceeds the overload event threshold which can be determined using BEC Analysis or any other means it will be recorded as an overload event The impact event is identified by examining the slope associated with the event If the slope exceeds the impact event threshold it will be recorded as an impact event Identification of the impact event involves examining three 28 parameters the start index the peak index and the event As illustrated in Figure 2 12 each parameter is expressed with bi and yi components where bi represents the time that the index or the event is recorded while yi represents their magnitude in strain These three parameters are used to find the slope within the strain record that contains the event Once the slope is determined the software checks to see if the slope exceeds the predefined impact threshold If exceeded the software will recognize the event as an impact event Note that the impact event threshold must be defined prior to running the field monitoring software This may require collecting sample strain data from ambient traffic to establish an appropriate strain rate b2 Strain Record M Peak Overload Event Peak Index Start Index Peak Event Event Detection Threshold E 52 Y1 Event Detection Threshold 4 Peak Event Overload Event Threshold Figure 2 12 Parameters u
107. cted sensor one by one and create a text file that will contain the filter parameters and event detection thresholds for all sensors The following tasks must be performed 49 21 Move to the Create File for Filter Parameter tab control 19 and check if the filter parameters and event detection thresholds for the selected sensor are stored in the table indicator 20 where each row represents the settings for the sensor specified in the first column named Sensor 22 Repeat steps xiii through step xix until the filter parameters and the event detection thresholds have been established for all sensors 23 Set the path 21 to which the filter parameters and event detection thresholds will be saved The default file name and directory is CASHM Folder Filter Paremeters txt 24 Click the Create File for Filter Parameters control 222 to create a text file that contains the filter parameters and event detection thresholds for all sensors 25 Click the STOP control 23 to stop the program 2 2 4 Main Data Acquisition and Processing Once the preliminary data collection and analysis have been completed the second group of the field monitoring software the SHM main data acquisition and processing can be initiated In general this involves two steps 1 input information settings and 2 main data acquisition processing and reduction that require running two programs 3 Input VI and 4
108. d 3 83 01 6 o1n3rq ewp o duues ojnurur c CF 3e 195 uonoojop yeod Asiy uens poonpur p p gt Vens 2 84 QT anat ewp o duues ojnurur F 3 198 yeod Asy weng 7 m 9NIH11NI981 1901808 LLL Ig _ i 4 ALISYJAINA ALVIS k En tum TI HH HABE lili it EE Hom di A 1 Tr M En HEUTE T 1 1 FT EAE 5 EI a t ot 0 i 8z 0121 2 0 9002 exea WHS 10 n o 38 EEE GSd 1 44 7 BUEd 30014 LA sISATEUY 85 3 4 2 System Validation In order to validate the accuracy of strain measurement from the SHM system an in service field test was conducted For this testing a strain measurement system from Bridge Diagnostics Inc BDI and two BDI stra
109. d Period Covered Iowa Highway Research Board Final Report Iowa Department of Transportation 14 Sponsoring Agency Code 800 Lincoln Way Ames IA 50010 15 Supplementary Notes 16 Abstract This report is divided into two volumes Volume I summarizes a structural health monitoring SHM system that was developed for the Iowa DOT to remotely and continuously monitor fatigue critical bridges FCB to aid in the detection of crack formation The developed FCB SHM system enables bridge owners to remotely monitor FCB for gradual or sudden damage formation The SHM system utilizes fiber bragg grating FBG fiber optic sensors FOSs to measure strains at critical locations The strain based SHM system is trained with measured performance data to identify typical bridge response when subjected to ambient traffic loads and that knowledge is used to evaluate newly collected data At specified intervals the SHM system autonomously generates evaluation reports that summarize the current behavior of the bridge The evaluation reports are collected and distributed to the bridge owner for interpretation and decision making This volume Volume II summarizes the development and demonstration of an autonomous continuous SHM system that can be used to monitor typical girder bridges The developed SHM system can be grouped into two main categories an office component and a field component The office component is a structural analysis software program that can be
110. d into the board s CN 115 header for channel 1 The dashed rectangle indicates the relative size and orientation of these options For both the CN 115 1 and the WBKI LC the two jumpers left edge of header must be removed Note B The CN 115 plug in adapter fits directly over the header When using a CN 115 the two jumpers Cleft edge of header must be installed as indicated in the figure Note C The CN 189 includes two 7 pad jumpers and 9 slot screw terminal block With use of the terminal block and appropriate shorting of jumper pads the user can casily configure the option to utilize the components of an installed CN 115 of CN 115 1 The CN 189 screw terminal option plugs into a DE connector Reference Notes amp Schematics of various bridge configurations can be found on pages 6 8 through 6 11 These configurations apply to both the CN 115 and the CN 115 1 TheWBKILC Load Cell Shunt Cal Internal Option is discussed on page 6 15 The CN 115 1 User Conflgurable Plug In Card performs the same function as the CN 115 Header Plug in Option CN 115 1 is discussed on page 6 20 connector information including use of the optional CN 189 adapter begins on page 6 12 1 Users Manual C 16 Bridge Applications All strain gage bridge configurations consist of a 4 element network of resistors The quarter half or fall designation of a strain gage refers to how many clements in the bridge are str
111. der and the order must be an even number 17 Enter event detection thresholds 713 that will be applied to the selected strain data The event detection thresholds should be determined such that peaks are not identified from the free vibration response of the bridge more detail will be discussed in Chapter 3 Once set only those events that exceed the event detection thresholds will be recognized by the program and displayed in indicator 17 18 Press the Plot Strain History control 14 to plot strain history and view the effects of filtering the selected strain data When pressed indicator 15 will display the selected sensor and the status indicator 16 will turn red indicating that plotting strain history is in progress 19 Upon completion the status indicator will turn bright green and a strain history plot for the selected sensor is displayed on the graph indicator 17 20 At this point the user needs to decide if the filter parameters used are adequate to minimize noise while identifying proper peaks or events If the user desires to alter the filter parameter settings new parameters need to be defined in 12 and the Plot Strain History control 14 needs to be pressed again Otherwise save the filter parameter settings for the selected sensor by pressing the Save Parameters for Selected Sensor control 18 The next task requires the user to check if the parameter settings are stored for each sele
112. detection thresholds will be recognized by the program and displayed in indicator 17 Press the Plot Strain History control 14 to plot strain history and view the effects of filtering the selected strain data When pressed indicator 15 will display the selected sensor and the status indicator 16 will turn red indicating that plotting strain history is in progress Upon completion the status indicator will turn bright green and a strain history plot for the selected sensor is displayed on the graph indicator 17 At this point the user needs to decide if the filter parameters used are adequate to minimize noise while identifying proper peaks or events If the user desires to alter the filter parameter settings new parameters need to be defined in 12 and the Plot Strain History 0 0435 dB zi B 4 control 14 needs to be pressed again Otherwise save the filter parameter settings for the selected sensor by pressing the Save Parameters for Selected Sensor control 18 The next task requires the user to check if the parameter settings are stored for each selected sensor one by one and create a text file that will contain the filter parameters and event detection thresholds for all sensors The following tasks must be performed Move to the Create File for Filter Parameter tab control 19 and check if the filter XXLX parameters and event detection thresholds for the selected sensor are stored i
113. different type daily weekly monthly and yearly of data file from provided tabs where the title of each tab represents a time duration for which one file is created and archived For example if users want to access information obtained during the second week of monitoring the user must select Weekly tab and enter a number 1 the text box Note that the index i starts from zero For 6 Create Report From Multiple Files VI users can access multiple data files given that those data files are already created and archived Three options are available as listed below d Up to date allows the user to access all daily data files created e Day 1 Day j allows to access multiple daily data files created during user specified time period f Last 1 days allows to access multiple daily files created during the last user specified days Note that except in the Up to date tab users can select a monitoring period by using the up and down arrows to increase or decrease number in the text box or simply type in the desired number Note 2 Plots of event history event histogram and statistical trends are displayed on separate tabs to avoid clutter on the front panel The appearance scale and format of any graphic display can be modified pan or zoom while the program is running or stopped through the use of the graphic palette located on the left bottom corner of each graph or by right clicking the graph and selecting Visi
114. directory Then new data files will be saved into the directory 3 Data File Folder 8 Run Button Control When pressed the program will begin 9 Input Information Tab Contains indicators that display the input settings Control specified by 3 Input VI Table B 5 Description of selected controls and indicators in 5 View Strain History VI Control or Indicator Description 1 Data File Path Control Path to the data file created during the data acquisition 2 Filter Parameters File Path to the text file that contains event detection Path Control thresholds and filter parameters for Chebyshev low pass filter 3 Sampling Rate Control Sampling rate at which strain records were collected Hz during the main data acquisition number of samples per second 4 Plot Strain History When pressed strain history will be displayed in Control indicator 6 for each sensor 5 Strain History Plot Provides the status of strain history plot progress If Progress Indicator being processed In Progress Wait is shown and turns red If completed Ready Done is shown and turns bright green 6 Graph Indicator Displays strain history in microstrain for each sensor 7 Stop Control When pressed the program will stop 8 Graph Palette Control Changes the scale and the format of the plot while the program is running or stopped B 20 Table B 6 Description of selected controls and indicato
115. e 12 Eisute2 lt 72 Load yy MANO eode ee Et S d is tee 16 Figure 2 8 Analysis WIHdON ed dr ie e cae esas adore 17 Figure 2 9 Print Maximums eee eee 19 Figure 2 10 View Data WIBdOWS o osc od eee dee ea cae nes 21 Figure 2 11 Plot Oy sessed aches 23 Figure 2 12 Parameters used to determine a slope in a strain record sss 29 Figure 2 13 Illustration of overall procedures involved in the field monitoring software 34 Figure 2 14 Screen shot of Preliminary DAQ VI front panel sse 35 Figure 2 15 Screen shot of 2 FFT PSD Analysis VI front panel see 36 Figure 2 16 Screen shot of 3 Input VI front panels rosas 39 Figure 2 17 Screen shots of 4 MainDAQ 815 VI front 2 40 Figure 2 18 Screen shot of 5 View Strain History VI front panel esee 42 Figure 2 19 Screen shot of 6 View Hourly File VI front panel serene 43 Figure 2 20 Screen shot of 7 Create Report From Single File VI front 44 Figure 2 21 Screen shot of 8 Create Report From Multiple Files VI front panel 45 Figure 2 22 Data file selection option for 7 Create Report From Single File VI 58 Figure 2 23 Data file selection option for 8 Cr
116. e if the user wants to access information obtained during the second week of monitoring the user must select Weekly tab and enter a number 1 the text box Note that the index i starts from zero For 6 Create Report From Multiple Files VI the user can access multiple data files given that those data files are already created and archived Three options are available as listed below a Up to date allows the user to access all daily data files created Figure 2 23a b Day 1 Day 1 allows to access multiple daily data files created during user specified time period Figure 2 23b c Last 1 days allows to access multiple daily files created during the last user specified days Figure 2 23c Note that except in the Up to date tab shown in Figure 2 23a the user can select a monitoring period by using the up and down arrows to increase or decrease number in the text box or simply type in the desired number Note 2 Plots of event history event histogram and statistical trends are displayed on separate tabs to avoid clutter on the front panel The appearance scale and format of any graphic display can be modified pan or zoom while the program is running or stopped through the use of the graphic palette located on the left bottom corner of each graph or by right clicking the graph and selecting Visible Items gt gt Graph Palette from the shortcut menu An example of the graphical indicator that displays history even
117. e boundary conditions for the exterior supports Three options are available fixed pin roller and rotational spring e A fixed support is a support that has all degrees of freedom restrained e Apinned roller support restrains only one or two degrees of freedom If a model bridge is built with more than two spans interior supports will be modeled as pin roller with full continuity between the adjacent spans e rotational spring support can be defined by inserting the appropriate corresponding rotational spring constants The spring constant must be between zero and infinity 2 1 2 2 Span Description Window The next step involves entering information about each span in the Span Description window 5 shown in Figure 2 5 in this window geometry member type material and section properties for each span are specified Up to ten Span Description windows will appear one by one depending upon the number of spans specified in 72 The input required for each Span Description window involves specifying the length of the span 6 followed by selection of member types and materials Two options are available in the Member Selection frame 7 e Prismatic member member size and section properties are constant along the span If selected controls 8 and 12 through 16 will be disabled e Non prismatic member member size and section properties are not constant along the span Up to five different sections with differe
118. e of the sponsors The sponsors assume no liability for the contents or use of the information contained in this document This report does not constitute a standard specification or regulation The sponsors do not endorse products or manufacturers Trademarks or manufacturers names appear in this report only because they are considered essential to the objective of the document Nondiscrimination Statement Iowa State University does not discriminate on the basis of race color age religion national origin sexual orientation gender identity sex marital status disability or status as a U S veteran Inquiries can be directed to the Director of Equal Opportunity and Diversity 515 294 7612 Technical Report Documentation Page 1 Report No 2 Government Accession No 3 Recipient s Catalog No IHRB Project TR 493 CTRE Project 03 135 4 Title and Subtitle 5 Report Date Evaluation of Steel Bridges Volume II Structural Health Monitoring System for December 2007 Secondary Road Bridges 6 Performing Organization Code 7 Author s 8 Performing Organization Report No Brent M Phares Terry J Wipf Yoon Si Lee and Justin D Doornink 9 Performing Organization Name and Address 10 Work Unit No TRAIS Center for Transportation Research and Education Iowa State University 11 Contract or Grant No 2711 South Loop Drive Suite 4700 Ames IA 50010 8664 12 Sponsoring Organization Name and Address 13 Type of Report an
119. e some effort to find a particular data file In order to address this issue these programs were programmed to find the correct file or files specified by user inputs The procedures involved in executing each of these programs are described in the following sections 2 2 5 1 Accessing Hourly Created Data Files 6 View Hourly File VI allows users to view event history event histogram and alarm messages from hourly created data files either within the front panel or in an Excel Worksheet Illustrated in Figure 2 19 is an example setting for 6 View Hourly File VI The following procedures are involved in running the program e Select the directory 1 in which the hourly data files are archived The default is set as C SHM Folder 3 Data File Folder If users want to access an hour file received via email the path to the folder that contains the received file must be selected e Select a monitoring period 2 The number in the text box indicates the hour since monitoring began starting with zero For example if the user wants to open an hour file that contains the event history obtained during the first hour of monitoring 0 must be entered if the user wants to access a hour file occurring 56 days 3 hours later the user would enter 1346 e To view the data file in an Excel Worksheet set the LED option 3 to true bright green e Configure the histogram setting 4 This option allows users to change five variable
120. eate Report From Multiple 58 Figure 2 24 Examples of event histogram and statistical trends sss 59 Figure 2 25 IOtech instrument hardware ceo reta adco etis ein e DURER ed 61 Figure 2 26 CormmonicatiOtUse Ss osos eter dese ate eni Qd e n pee 62 Figure 3 1 Overall bridge photographs sua a eed eee eode 64 Figure 3 2 Framing plan and typical cross section of the bridge sss 65 Figure 5 5 Plate girder debat p Wage 66 Figure 3 4 Bridge strain gage location and reference sections 69 Figure 3 5 Environmentally controlled cabinet containing the monitoring equipments 70 Figure 3 6 Plate girders divided into sections a cosa mise cci node cb ecd de ee Se 72 Figure 3 7 Analytical moments due to Iowa legal truck Type 3 at the sensor locations with respect to the first axle position scd Dus Dep chest 76 Figure 3 8 PSD plot from sample data with no traffic on the bridge 2 2 4 2 2 79 Figure 3 9 PSD plot from sample data with traffic on the bridge sss 80 Figure 3 10 Illustration of effect on filter parameters and peak detection thresholds 81 Figure 3 11 Examples of in service validation testing comparison of measured strains collected by the BDI system and the SHM
121. ed E P1 Cable End 089 male assembled metal hood with thumbscrews solder cup DBS P2 Cable End Unterminated blunt cut Cable Type Belden 3614 or equivalent Wire Gauge 24 AWG Outer Shield Foil and 65 braid Number of Conductors Nine 8 plus drain Dimensions Length 72 4 Connector width 1 220 maximum P1 to P2 Pinout Specifications As indicated at left Cable DB9 numbering is opposite of that found on the StrainBoak to allow for correct pin mating CN 189 DB9 Adapter Option Remove the Strain Book from power and disconnect the unit from the host PC and from all externally connected equipment prior to connecting cables signal lines and or removing the cover to install or remove components Electric shock or damage to equipment can result even under low voltage conditions Take ESD precautions packaging proper handling grounded wrist strap etc Use care to avoid touching board surfaces and onboard components Only handle boards by their edges or ORBs if applicable Ensure boards do not come into contact with foreign elements such as oils water and industrial particulate channel or b will be used alone then the associated channel s CN 115 9 If the C N 189 will be used with CN 115 installed in the associated header jumpers must be installed as indicated in the figure The CN 189 option consists of two 7 pad jumpers and P4 a DEO connec
122. ed frequency range with a significant content detected at 4 8 Hz that appears in all PSD plots As shown in Figure 3 9 it appears that the forced vibration frequencies are in the range of from 0 to 1 Hz In addition the fundamental frequency caused by free vibration the first mode of the ambient traffic was detected at approximately 2 8 Hz in all sensors Also it can be seen that there is a notable frequency at 4 8 Hz which is the same as was observed without any traffic present Once the PSD plots were generated and the noise induced and traffic induced frequency contents were investigated three filter parameters for the lowpass frequency filter 1 cutoff frequency filter order and ripple and peak detection thresholds described in Chapter 2 were determined for each sensor The purpose in determining the filter parameters is to eliminate or minimize the noise Based upon the generated PSD data it was decided to set the cutoff frequency at 2 8 Hz With this setting although it did not eliminate all of the noise in the measured strain record it allowed passage of the most dominant live load frequencies The ripple and filter order for each sensor was determined based on the explanations and recommendations discussed in The Scientist and Engineer s Guide to Digital Signal Filter Processing 4 and LabVIEW Analysis Concepts 5 The peak detection thresholds were set at 5 microstrain for all sensors This value was determined so that it would n
123. edge is used to evaluate newly collected data At specified intervals the SHM system autonomously generates evaluation reports that summarize the current behavior of the bridge The evaluation reports are collected and distributed to the bridge owner for interpretation and decision making This volume Volume II summarizes the development and demonstration of an autonomous continuous SHM system that can be used to monitor typical girder bridges The developed SHM system can be grouped into two main categories an office component and a field component The office component is a structural analysis software program that can be used to generate thresholds which are used for identifying isolated events The field component includes hardware and field monitoring software which performs data processing and evaluation The hardware system consists of sensors data acquisition equipment and a communication system backbone The field monitoring software has been developed such that once started it will operate autonomously with minimal user interaction In general the SHM system features two key uses First the system can be integrated into an active bridge management system that tracks usage and structural changes Second the system helps owners to identify overload occurrence damage and deterioration xiii 1 INTRODUCTION 1 1 Background The ability to monitor the condition of a bridge to ensure its safe usage and to be able to effectively mana
124. een with a mouse click and other options must remain unselected dark green Six options are available as follows g Hourly Data allows users to receive hourly generated reduced data files each of which contains event history in the preceding hour h Daily Data allows users to receive daily generated data files each of which contains event history in a day i Weekly Data allows users to receive weekly generated data files each of which contains event history in the preceding week j Monthly Data allows users to receive monthly generated data files each of which contains event history in the preceding month k Yearly Data allows users to receive yearly generated data files each of which contains event history in the preceding year 1 Alarm Message allows users to receive a text message of an alarm event upon occurrence Enter email information that the reduced data files are sent from to 10 and set the LED option Check if email inputs are entered to true bright green by a mouse click to activate this option within 4 MainDAQ VI Three pieces of information are required d Return address email address of the file and or message sender xliii xliv xlv xlvi xlvii xlviii xlix e Mail server the name or IP address of an SMTP server f Recipients email addresses of the file and or message recipients Each address can be a separate array element Apply the calibration file 11 which was created during
125. einforced concrete slab The bridge deck is supported by two exterior plate girders and two WF 18x45 interior stringers The primary structural members are the two plate girders as the stringers are supported by floor beams which are then supported by the plate girders The spacing between the exterior plate girder and the interior stringer is 9 ft while the interior stringers are spaced at 8 ft as shown in Figure 3 2 The sizes of the plate girder flanges are variable as shown in Figure 3 3 The abutments are stub reinforced concrete and the piers consist of concrete columns Both the abutments and the piers that support the plate girders have rocker type bearings and the bridge is skewed 20 degrees 63 East bound Bridge West bound Bridge Selected for System Demonstration a End view looking east b Side view looking south east Stringer Floor Beam Girder Figure 3 1 Overall bridge photographs 64 i ISPLIG IY Jo 85022 8 c c 00295 55010 eo1d L q 497 0 6 0 8 076 497 1 5 NVA X00714 d HSONDULS Y WANAAAILS EL p 0705 ueyd 4 v 49 46 07501 49 46 676 5 6 49 6 0 61 01706 01 0 01 08 0 91 AT 91 01 06 01706 01706 01706 eH 791 0791 01 08 01706 01706 Y 1
126. elect the box and enter number between 1000000 and 1000000 This value must be less than eppliedIcad value The fill option is Sio for this colum sos Uns 8 4 calbration method The number must equal the input in aie test point in the To changa the valus select the and enter a number between 10000 and This column is for calbrapng any sensor using the Shunt 2 Point Automatic or 2 Manual calibration meod The number must equal the valus in the selected units of me first point calibration To change the value Select the box and enter number between 1000000 and 1000020 The fill opson is avafable for this column see Uses for cal avg any sensor using t 2 Poirt methoc nurnber must equal the input value in mV o ofthe pont in the calibration To the value select the box and enter number between 10000 and 10000 The fil option is avallabie for this column see Units This colum is used for any sensor using the 2 Poirt Automatic or 2 Point Manual calibration method The number must equal the value in Me selected units of the second point in the calibration To change the value select the bax end enter between 1000000 and 1000000 The fill option is available for this see Units eri StrainBaclo6 16 User s Manual C 28 The Shunt calibration method pertains to an internal shunt For this method t
127. emove the plug from the main board then solder resistors to the adapter plug as indicated To avoid damaging the pin alignment on the plug solder with minimal heat After soldering the resistor Sbidering Resistors to leads should be snipped off close to the support Adapter Plug StrainBoows16 User s Manual 925494 Bridge Configurations 6 5 C 19 Installing a CN 115 Remove the StrainBook from power and disconnect the unit from the host PC and from all externally connected equipment prior to connecting cables signal lines and or removing the cover to install or remove components Electric shock or damage to equipment can result even under low voltage conditions Take ESD precautions packaging proper handling grounded wrist strap etc Use care to avoid touching board surfaces and onboard components Only handle boards by their edges or ORBs if applicable Ensure boards do not come into contact with foreign elements such as oils water and industrial particulate bridge completion headers CN 115 from the unit before soldering resistors in the headers 49 Be careful to avoid bending the pins and ensure that the plug in is correctly oriented A Be careful to avoid component damage while the StrainBook is open Always remove Note that the associated channel s two jumpers located on the Strain Book board must be installed for CN 115 applications but removed for CN 115 1 or WBK16 LC applications You can eas
128. er member size and section properties are not constant along the span Up to 5 different sections can be defined within a span by using controls 8 through 716 78 Member Type Frame Allows modeling a non prismatic span with a stepwise approximation by dividing into up to 5 prismatic segments Although using more segments will result more accurate analysis processing time will be longer 9 Member Cross Section Frame Allows users to define or select sections for a member from a database included in the program Four options are available e Define see 22 e Standard Steel see 32 see 35 e AASHTO P C see 37 10 Beam Material Frame Type of member material in each span Upon selection either steel or concrete corresponding elastic modulus will be assigned in 11 11 E ksi Control Modulus of elasticity of either 29000 ksi or 3640 ksi will be automatically assigned depending on the material type selected in 10 A different value can be assigned by simply typing in a desired value 12 Calculator Command Used to calculate section properties in each member segment When pressed a Section Properties window will appear 13 Ti Control Moment of inertia for each segment either to be entered or computed by the Calculator 12 14 Si Control Section modulus for each segment at a sensor location specified in 25 If a sensor location is not specified the default will be the
129. erical counts of events identified in the stringers Sensor 2 vs Sensor 3 and Sensor 6 vs Sensor 7 e From reviewing the number of identified events in Table 3 6 and Figure 3 12 relatively fewer events were identified from the sensors installed on the stringers than on the plate girders One possible reason could be the peak detection thresholds that were used in the data processing Typically the magnitudes of the measured strains in the stringers are smaller than those in the plate girders In order to provide hour to hour day to day and week to week comparisons of the bridge response 24 hour hourly event histograms and 30 day daily as well as weekly event histograms for Sensor 4 typical of all sensors were created and presented in Figures 3 13 and 3 14 After reviewing and comparing the histograms several observations were made as follows e The numerical counts of identified events are different from hour to hour day to day and week to week as expected The variation in the number of identified events within the daily and weekly event histograms is less than that within the hourly event histogram This was expected as hour to hour traffic patterns vary more than day to day or week to week traffic patterns e Although it does not represent exact traffic counts the variation in the number of identified events within one chart is directly related to the traffic volume traversing the bridge in a given period e Examining the hourly event
130. essage recipients Each address can be a separate array element Apply the calibration file 11 which was created during the sensor calibration 51 process by setting the LED option to true bright green and by assigning the calibration file path e Designate the folder directory in which raw strain data file are to be written and saved 12 The default is C SHM Folder Raw Data This is one of the sub directories created during the initial setup see Section 2 2 2 2 e Designate the folder directory to which the raw data are moved for data reduction and evaluation 13 The default is C SHM Folder Data Process This is one of the sub directories created during the initial setup see Section 2 2 2 2 e Designate the folder directory in which all the reduced data files Hourly Daily Weekly Monthly and Yearly Data files will be saved The default is CASHM Folder 3 Data File Folder This is one of the sub directories created during the initial setup see Section 2 2 2 2 e Set the path 15 for the filter parameters file that contains the event detection thresholds and filter parameters Once the input settings are entered users can execute the program by pressing the Create and Save Input File control 16 This will result in the creation of a DAQ Inputs file in the main directory C SHM Folder Inputs The last step is to stop the program by pressing the STOP control 17 2 2 4 2 M
131. ethod 11 Shunt Rd Exc Volts 12 5V Gage Factor 13 2 0 Shunt Resistor 14 57983 Bridge Resistor 15 350 Max Appl Load 16 3000 o Point 1 17 3000 Ixxviii Click Calibration Enabled Channel 18 to calibrate the selected channels Ixxix Once the calibration is completed click Close 19 and save the calibration file WaveView WAVEVIEW CFG StrainBook_0 Edt Sytem 1 mE x E E7 53 CN u Charra Cor guraton Bdge 1 4 2220o0ocoo 5 cum CHi Figure C 1 3 WaveView WAVEVIEW CFG St t View em oie Channel Configuration E blew GEH Bridge Type 1 4 Bridge v mm 2 CH On off Lebel Readings Units ace Pus LPF Catof ee Invert SSH 20 1 CHO1 0 mv 30310303 No 0 Bypass 10 00 DC 50V l 4Bridge No Bypassed 0 2 D mv 30310303 0 Bypass 10 00 DC 50V 1 4Bridge No Bypassed 0 3 CH03 0 mv 30 3t0 303 0 Bypass 10 00 DC 50v 1 4Bridge No Bypassed 0 4 On CH04 0 mv 30310303 0 Bypass 10 00 DC 50v 1 4Bridge No Bypassed 0 5 On CHO5 0 mv 30 310303 D Bypass 10 00 DC 50V 1 4Bridge No Bypassed 0 6 On 0 mv 30310303 0 Bypass 10 00 DC 50V 1 4Bridge No Bypassed 0 7 On CH
132. f P1 is measured from the left exterior support It is illustrated as b1 in Axle Configuration display 51 and in 68 63 Progress Bar Indicator Shows the analysis progress 64 Exit Command When pressed the program will be terminated 65 Number of Analysis Points Beam Control Number of analysis points for each span that will be used during the analysis While more analysis points will generate more accurate analysis the processing time will be longer 66 Maximum Results Indicators Displays the maximum positive and negative moments and strains in each span 67 Location of Maximum Results Indicators Displays locations at which maximum results are generated in each span 68 First Axle Position Indicators Displays locations of P1 first axle that generated the maximum results in each span 69 Print Maximums Window Allows user to print the absolute maximums generated during the analysis 70 Margin Frame Allows users to set margins top and left on a standard paper size 71 Print Command When pressed the absolute maximum will be printed out 72 View Data Command Allows users to retrieve and view the maximums generated according to the option selected either 53 or 54 and input specified in 65 73 Output Image Display Box Displays an output image to be printed 74 View Data Window Allows users to view and or save data of the maximum envelopes or moment and str
133. ge its operation is of significant interest to bridge owners Over the decades the most widely used condition monitoring methods rely on subjective incremental visual assessments or localized testing techniques However these techniques often require traffic control to be implemented and may not be sensitive enough to identify damage and or deterioration over time In order to address this issue the Iowa State University ISU Bridge Engineering Center developed an autonomous continuous structural health monitoring SHM system that can be used to monitor typical girder bridges The developed system features two key uses First the system can be integrated into an active bridge management system to track usage and structural changes Second the system helps owners to identify overload occurrence vehicle collision to the structure damage and deterioration In the recent past there have been rapid advances in the development of the technologies needed for effective SHM SHM is a relatively new but fast growing field within the bridge engineering community In short SHM is the process of evaluating the condition or change in behavior of a bridge over time using quantitatively measured response data complemented with advanced data analysis When properly designed a SHM system has a distinct advantage over conventional monitoring techniques in that at any point during monitoring period the overall condition of the bridge can be evaluated without sub
134. he Upon Program Exit to Restart the Program and enter the time for which the program is forced to wait before it automatically resumes 60000 ms recommended d Click Install to install 4 MainDAQS15 EXE as a service program If successfully installed a prompt dialog box will appear indicating that the installation process is completed Fig D 4 and the service program created will be listed in the FireDaemon Pro Service Manager window as shown in Fig D 5 FireDaemon 1 Service MainDAQ815 successfully installed Figure D 4 Prompt dialog box FireNaemon Pro Service Manager v1 7 Fle Sewce 2 Sewke Stans Prozess Statu User Seven Monza Hue 03 xy donato Figure D 5 FireDaemon Pro Service Manager window service 9815 installed APPENDIX E Plots of the theoretical moments and strain due to each design load 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 1000 500 Moment or Strain 50 400 500 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2000 Moment ft kips Strain microstrain West Pier 1500 1000 500 Moment or Strain 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 1 Moments
135. he SHM system can be principally grouped into two main categories an office component and a field component The office component is basically a structural analysis software program that can be used to generate thresholds which will be used for identifying isolated events The field component includes hardware and the field monitoring software which performs data processing and evaluation The hardware system consists of sensors data acquisition equipment and a communication system backbone The field monitoring software has been developed such that once started it will operate autonomously with minimal user interaction In general the SHM system features two key uses First the system can be integrated into an active bridge management system that tracks usage and structural changes Second the system helps owners to identify damage and deterioration This report has documented three distinct work tasks performed to accomplish the objective The first two tasks involved developing the SHM system while the last task was to demonstrate the system A brief summary of the individual tasks follows The first task involved developing the live load structural analysis software BEC Analysis In Section 2 1 the general effort given in the development and the components and features of BEC Analysis were described The algorithm was based upon classical beam theory and the direct stiffness method of matrix structural analysis The analytical methods used in BE
136. hich the data files are archived The default is set to C SHM Folder Data File Folder In the Monitoring Period control 2 select data file s to be plotted and processed for the report generation See Note 1 below for detailed description e To view the data file in an Excel Worksheet set the LED option 3 to true bright green e Select the print options 4 This allows the user to print the report either or both in a paper copy or and in PDF format given that corresponding option s are selected bright green e Select the report content options 5 This allows the user to choose the contents that will be included in the report Four options are available a Strain histogram numeric table numerical count of events in each bin where the bin size is specified by users b Strain histogram graph graphical representation of numerical count of events c Statistic Trends numeric table numerical values of absolute maximum events average events hourly or daily depending upon the data file selected and average trend line over the selected monitoring period d Statistic Trends graph graphical representation of events over the selected monitoring period e Configure the event histogram variables 6 This option allows users to change five variables number of bins and maximum and minimum bins for positive and negative events e Press the Click to Create Report control 7 to execute the progr
137. hrough a network device Some network devices such as a wireless access point WAP or a router may be used as a connector Note that the field monitoring software was programmed to work for both situations Sensors a Direct connection from the host PC to the Device Local Network DX End Users Bridge Site Network Device f 666 lo b Connection with a network device Figure 2 26 Communication schematics 62 3 SYSTEM DEMONSTRATION The developed SHM system was tested and implemented on a US 30 highway bridge in order to demonstrate and verify its general usage The following sections summarize this demonstration 3 1 Bridge Description The bridge selected for demonstrating the use of the SHM system is the 320 ft x 30 ft three span continuous welded steel girder bridge shown in Figure 3 1 The bridge is located in central Iowa in Story County IA carrying US Highway 30 US 30 over the Skunk River near Ames IA The bridge consists of two 97 5 ft end spans and a 125 ft center span The bridge girders are spliced at locations 30 ft from the two piers in all spans The roadway width is 30 ft allowing two traffic lanes and a narrow shoulder on each side The bridge has moderate curbs that are integral with the deck and concrete guardrails connected to the curbs The bridge deck is a nominal 7 V4 in thick cast in place r
138. ically selected by the software when needed Internal 1 MQ shunt resistors are used to avoid open circuits These resistors are not suitable for high accuracy low noise applications A quarter bridge gage additionally requires a resistor of equal value to itself Up to 3 different values may be installed simukaneously in header positions Ra Re Re All of these resistors are connected to the excitation terminal An extemal jumper at the input connector determines which resistor is utilized Therefore 3 different quarter bridge values can be supported without opening the enclosure Each different value bridge would simply have the jumper in a different location when the gage is plugeed in the proper resistor is then already selected Configurations with the completion resistor on the excitation are redundant due to the internal inversion stage and not used EXE Kelvin Excitation Leads upcoming strain gage configurations are presented in 4 groups Pull bridge half bridge quarter bridge and high gain voltmeter Many of these configurations can coexist but are shown individually for clarity StreinBoodG 6 Users Manual Bridge Configuratons 62 C 17 Removing the Cover Plate Remove the Strain Book from power and disconnect the unit from the host PC and from all externally connected equipment prior to connecting cables signal lines and or removing the cover to install or remove compone
139. idge are also presented The information regarding functions of each VI and its procedures were explained in Chapter 2 Therefore only brief descriptions are presented in the subsequent sections 3 4 1 Sample Data Collection and Noise Minimization As mentioned in Chapter 2 measured strain data contains various components that include traffic induced strains and other unwanted elements such as changes in strain induced by drift and noise The useful information for the system developed herein is that resulting from ambient traffic only The effect of drift is eliminated by the data processing algorithm The minimization of noise requires blocking the source of the noise with filtering This is accomplished by running 2 FFT PSD Analysis VI with data collected with 1 Preliminary DAQ VI Following the general procedures provided previously numerous data sets including those with no traffic and those with ambient traffic traversing the bridge were collected After data collection each data set was investigated for the identification of noise and traffic induced frequencies After the PSD plots were generated comparisons were made to determine a suitable cutoff frequency Presented in Figures 3 8 and 3 9 are the resulting PSD plots that illustrated frequency contents within the measured strain recorded with and without traffic respectively From Figure 3 8 it can be seen that the noise induced frequencies are distributed throughout the display
140. ii Perform the step i through step v but this time select a data file that contains traffic plus noise induced strain Select a sensor with a mouse click within control 8 and move to the Strain History tab 11 Enter three filter parameters 12 that will be applied to the selected strain data cutoff frequency Hz ripple dB and filter order d The cutoff frequency is determined by investigating dominant frequencies of traffic plus and noise induced and noise alone induced e Aripple of 0 0435 dB which is equivalent to 0 596 passband allowable error is set as a default as it is often a good choice for digital filters 4 The 0 5 passband allowable error was converted to 0 0435 ripple in dB as follows 100 2 100 f The order of a Chebyshev filter is equal to the number of poles in the transfer function of the filter In general a filter is considered to work better with more poles However this may not be always true Therefore several attempts trial and error may be necessary to determine the appropriate filter order The default is set as 2 order and the order must be an even number Enter event detection thresholds 13 that will be applied to the selected strain data The event detection thresholds should be determined such that peaks are not identified from the free vibration response of the bridge more detail will be discussed in Chapter 3 Once set only those events that exceed the event
141. ily install a CN 115 as follows Note Ifyou need to add or remove resistors to the CN 115 plug in do so prior to the installing it Configuration diagrams begin on page 6 8 Review the preceding CAUTIONS Remove the StrainBook or WBK16 from power and disconnect the unit from all external devices and signals Observe proper precautions Remove the cover from the StrainBook or WBK16 Locate the CN 115 channel headers m which the plug in is to be installed If the header socket occupied remove the CN 115 1 WBK16 LC previous CN 11510 expose the header socket Add one shunt jumper to each of the two 3 headers The 3 pin headers are located at the edge of the CN 115 16 pin header sockets see figures Note For each channel the jumper headers are labeled in sets of two JP101 JPT02 foe channel 1 through JP801 7P802 for channel 8 The first digit after JP signifies the associated channel number amp Carefully plug the CN 115 into the header socket 9 Re install the cover to the StrainBook ce WEKI 6 pe es B ENG HN 1 2 amp 3 CN 115 Headers for Channels 1 and 2 Required Jumper Placement for CN 115 Plug in Channel 1 has jumpers removed Channel 1 has no For each channel that has CN 115 installed CN 115 installed Channel 2 shows CN 115 pins must be jumpered as indicated above Each installed and proper jumper installation channel has jumper header next to
142. in 1 2 0 1378 49 3283 6 3896 T 2459 01 9552 1 9261 0 1915 47 2561 14 20 809 3 597 1 877 3 846 9 736 9 917 0 101 98 101 87 40 245 6 34 223 489 630 133 576 360 3 60 271 2 3 201 500 296 594 260 0 80 452 13 919 100 56 22 120 5 140 1 0 160 1 0 180 0 Total 1491 3884 4796 2636 1041 93 1034 2081 25 2734 57 91 240 220 j Dverload event threshold vent 204 H o Microstrain 8 8 5 160000 Event Counts a 30 day event history for Sensor 1 240 140 e 1 5 amp 120 a gt B 2 1004 5 80 50 40 20 9 gt 4 2 0 T T T T T T T T T T T T T T T T T T T T rV T T 1 0 1 23 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Day b 30 day daily statistical trends for Sensor 1 Figure 3 12 Monthly evaluation from on Nov 14 through Dec 14 of 2006 92 i 3 Microstrain 5 2500 5000 7500 10000 12500 15000 17500 20000 22500 25000 27500 30000 32500 35000 37500 40000 Event Counts c 30 day event history for Sensor 2 Microstrain m Daily Maximum Daily Average Daily Average Fit 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
143. in transducers were utilized with each strain transducer installed next to the weldable strain gages approximately 6 in apart in the west end span 1 Sensor 5 and Sensor 8 Once the BDI system was setup strains of randomly selected segments of ambient traffic were simultaneously collected by the SHM system and the BDI system and the measured strains from both systems were compared Figure 3 11 presents a representative example of the comparison between the measured strains obtained by both systems By comparing the strains obtained by both systems it was observed that both systems produced fairly consistent strains In general the overall discrepancies in measured strains were less than 5 ue and therefore the SHM system was thought to be performing accurately 86 100 StrainBook BDI Microstrain 100 Time second a Sensor 5 80 StrainBook BDI 60 40 20 Microstrain 20 40 Time second b Sensor 8 Figure 3 11 Examples of in service validation testing comparison of measured strains collected by the BDI system and the SHM system 3 4 3 Input Settings and Main Data Acquisition Processing After the hardware components had been installed and the filter parameters and peak detection thresholds determined 3 Input VI was run following the procedures described previously and a binary file DAQ Inputs that contains
144. input settings was created and saved in the main directory as was previously shown The input settings that were used in 3 Input VI were exactly the same 87 as the example depicted in Figure 2 16 except the magnitude of the overload event thresholds for the select sensors and the email address information After the DAQ Inputs file was created and saved in the main directory the main program designed for data acquisition and processing 4 MainDA Q815 VI was initialized at approximately 3 pm on November 14 2006 after which continuous data collecting and processing have been completely autonomous and have required no intervention except when reviewing and generating evaluation reports The following section presents a 30 day evaluation report obtained during the monitored period from 3 00 pm on November 14 2006 to 4 47 pm on December 14 2006 During this monitoring period a total of 755 data files including 720 hour files 30 day files 4 week files and a single month file were created and archived 3 4 4 Bridge Performance Evaluation Report As previously mentioned the three main purposes of the SHM system are to identify alarm events to investigate gradual changes in structural response of the bridge that would provide users with information regarding damage and to provide information on overall bridge usage Such information can be obtained directly from reviewing the evaluation report The evaluation report presented in this section
145. ions The prices in 2006 of the StrainBook 616 and the WBK16 expansion module are 6 000 and 4 000 per unit respectively 60 Courtesy of IOtech a StrainBook 616 with 8 built in strain channels Courtesy of IOtech b WBK16 8 channel expansion module Figure 2 25 IOtech instrument hardware 2 3 3 Communication System As with any typical SHM system that involves data acquisition and processing acquired data need to be transferred to a host PC for data processing and evaluation For data storage and delivery to users two scenarios may be considered once the acquired data are processed and evaluated necessary information regarding bridge performance can be either 1 stored in the host PC that is connected to the data acquisition instrument for later retrieval or 2 sent to users at other location Illustrated in Figures 2 26a and 2 26b are the two possible communication schematics The StrainBook 616 is capable of connecting both directly to an Ethernet port on the host PC or to a network hub or router via its built in 10 100BaseT Ethernet interface Note that either a straight through or a cross over cable can be used to connect between instruments For the first case the communication between the data acquisition instrument and the host PC can be accomplished by simply using Ethernet cable alone The later case requires a network or Internet connection In this case the 61 StrainBook 616 is connected to the Ethernet t
146. jectivity and without the need to physically be at the bridge Numerous tools and technologies currently available as well as emerging associated with SHM applications have been well publicized 1 2 The main issue now facing the bridge engineering community is not the lack of technologies that are available for SHM application but rather how to accurately analyze a target bridge or its members and how to process continuously collected data such that the useful information can be extracted and used It is also important that a SHM system be capable of monitoring long term phenomena as well as capturing short term events In addition the output of a SHM system must provide clear usable benefits to bridge owners rather than inundating them with massive amounts of disjointed data Such a need requires the development of a comprehensive approach to data management that also includes the development of high performance localized data processing and evaluation algorithms Significant effort has been given in the work summarized here to include data processing and evaluation algorithms that are based upon strong engineering principles while also taking full advantage of advanced data processing techniques 1 2 Objective and Product The primary objective of this research was to develop a continuous SHM system that can be used to monitor typical girder bridges for detecting and identifying overload occurrence vehicle collision to the structure change
147. k administrator with the information on the device s MAC label Also find out from the administrator if the IP Address will be changing If so see if you can obtain a permanent IP Address dedicated specifically to your device 5 12 Setup and Connecting to the Ethemet StrainBook 6 16 User s Manual C 13 4 Test the system connections b 79 Make sure the device has been properly installed and is powered on Make sure all cables are properly and securely connected Click the Test Hardware tab Click the TCP IP Test gt button This tests the Transmission Control Protocol Intermet Protocol The test results have two components Pinging Device and TCP Comection TCPAP and Resource Tests includes a brief explanation of each Upon completion of the TCP IP test click the Resource Test gt button The Resource Test consists of two components Resource Tests and Performance Tests Appendix B TCPAP and Resource Tests inchades a brief explanation of cach When testing a StrainBook 616 if the unit does not respond after 30 seconds perform the following steps 1 reboot the system 2 upon power up re open the Dag Configuration applet 3 select another configuration setting 4 reinitiate the test This completes the procedure for connecting a StrainBook 616 to the Ethernet At this point you should refer to other sections of the manual e g information on system expansion
148. lay the data file read progress When the data file reading is completed the total number of sensors used during the preliminary data acquisition will be displayed Upon completion of the FFT PSD analysis the status indicator 6 will turn bright green indicating that PSD plots for each sensor are ready to be viewed Select a sensor with a mouse click within control 8 Then the indicator 9 will display the selected sensor and a PSD plot for the selected sensor will be displayed in indicator 10 Identify the dominant frequencies from ambient traffic plus noise or noise alone depending upon a sample file selected and determine the desired cutoff frequency for the filter note more detail on how to determine the desired cutoff frequency will be discussed in Chapter 3 Move to the Strain History tab control 11 and enter the cutoff frequency determined in step vii Click the Plot Strain History control 14 to see the effect of filtering for the selected sensor Indicator 17 will display the strain history Go back to the FFT PSD Analysis tab control 2 and repeat step vi through step ix to see the effect of filtering for all sensors Repeat the step 7 through step x until an appropriate cutoff frequency is determined This may require examining several data files one at a time By comparing the dominant frequencies of traffic plus noise induced and noise alone induced an appropriate cutoff
149. lect a member with a mouse click If selected its label will be highlighted in blue and corresponding section properties for the selected member will be displayed in 34 39 Load Window Allows users to configure live loads that will be applied as moving live loads to a model bridge The Load window provides options for Iowa legal loads HS 20 trucks truck train as well as user defined live loads In addition distribution factor DF and impact allowance IM are input here 740 Iowa Legal Loads HS 20 Option Option for applying either pre defined Iowa legal loads the H 20 or the HS 20 trucks to a model bridge Selecting this option will enable the Iowa Legal Loads HS 20 frame 46 that lists available types of trucks 741 Truck Train Option Option for applying truck train to a model bridge Selecting this option will enable the W control 43 and the Apply W on frame 45 742 Define Number of Axles Option Option for applying a series of point loads up to eight that represent axles of a truck 43 W Control Magnitude of uniformly distributed load in kips ft that will be applied on selected span s of a model bridge if the Truck Train option 41 is selected 744 Number of Axles Control Number of axles that will be applied as moving live loads to the model bridge Up to eight axles can be specified 45 Apply W on Frame Lists span s in which a uniformly distributed load will be applied The uniforml
150. lected in 7 Also note that the graphic display in 17 will display how a member is segmented in each span A different graphic will be displayed according to the options selected in 7 and 8 Bridge Information e Number of Spans Boundary Conditions Span Description Member Type Pre processing Member Consistency Material Type Section Properties Load Load Type Configuration Distribution Factor Dynamic Impact Allowance Analysis e Absolute Maximums Moment Strain vs Truck Analysis Position e Maximum Envelopes Print Save Plot e Print Absolute Maximums e View and or Save Tabular Results Post processing e Graphical Representation of Analysis Results Figure 2 2 General flowchart illustrating the overall operation of BEC Analysis Bridge Information E lx BEC ANALYSIS A Live Load Structural Analysis Program for Bridge Structures and Components C Copyright lowa State University Bridge Engineering Center though the program is believed to be accurate outputs or results of BEC Analysis should not be utlized without user verification of the accuracy suitability and applicability of results The developer of BEC Analysis disclaims any liability arising trom the usage of BEC Analysis Chick to START IOWA STATE UNIVERSITY OF SCIENCE AND TECHNOLOGY BRIDG Figure 2 3 BEC Analysis title screen Bridge Information General Information Number of Spans
151. lected strain data in the US30 bridge e If properly implemented the developed system will allow owners to monitor and control overloads and provide better access to valuable traffic information that can be used in planning maintenance and construction activities Another benefit of the system is its relative ease of implementation and relative low cost Overall the objective of the project was successfully accomplished and it is believed that the use of the SHM system developed herein will provide owners the tools to better manage bridge assets 104 5 REFERENCES Aktan F N Catbas Grimmelsman and M Pervizpour Development of a Model Health Monitoring Guide for Major Bridges Drexel Intelligent Infrastructure and Transportation Safety Institute Drexel University Philadelphia PA 2003 Phares B M T J Wipf L F Greimann and Y S Lee Health Monitoring of Bridge Structures and Components Using Smart Structure Technology Center for Transportation Research and Education Iowa State University Ames IA 2005 American Association of State Highway and Transportation Officials Standard Specifications for Highway Bridges 16 ed Washington DC 1996 Smith S W The Scientist and Engineer s Guide to Digital Signal Processing California Technical Publishing 640 pp 1997 Also available online at http www dspguide com last accessed on April 2007 National Instruments LabVIEW Analysis Concepts National
152. ler pinned roller pinned roller e Span length o West end span Span 1 97 5 ft o Center span Span 2 125 ft o East end span Span 3 97 5 ft Concrete slab cross section dimensions and material property o Modulus of elasticity 3640 ksi o Thickness 7 25 in o Effective Width 87 in e Plate girder material property o Modulus of elasticity E 29000 ksi e Plate girder cross section dimensions in the west end span Span 1 Section Top Flange inches Web inches Bottom Flange inches 1 12 0 75 74 x 0 4375 13x 1 5 2 20 5x 1 5 74 x 0 4375 20 5x 1 5 3 28 x 01 5 74 x 0 4375 28x 1 5 e Plate girder cross section dimensions in the center span Span 2 Section Top Flange inches Web inches Bottom Flange inches 1 28 1 5 74 x 0 4375 28 x 1 5 2 20 x 1 5 74 x 0 4375 20 5 x 1 5 3 12 x 0 75 74 x 0 4375 13 1 5 4 20 1 5 74 x 0 4375 20 5 x 1 5 5 28 x 1 5 74 x 0 4375 28x 1 5 71 e Plate girder cross section dimensions in the east end span Span 3 Section Top Flange inches Web inches Bottom Flange inches 1 28x 1 5 74 x 0 4375 28x 1 5 2 20 x 1 5 74 x 0 4375 20 5 x 1 5 3 12x 0 75 74 x 0 4375 13x 1 5 e Distribution factor DF and impact allowance IM were determined in accordance with the AASHTO Standard Specifications for Highway Bridges 16 edition 3 to be o DF 2 769 o IM 22 for the west end span and 20 for the center span 1 2 3 67 6 26 0 4 0
153. ll display the selected sensor and a PSD plot for the selected sensor will be displayed in indicator 10 Identify the dominant frequencies from ambient traffic plus noise or noise alone depending upon a sample file selected and determine the desired cutoff frequency for the filter note more detail on how to determine the desired cutoff frequency will be discussed in Chapter 3 B 3 xviii xix Xx xxi Move to the Strain History tab control 11 and enter the cutoff frequency determined in step vii Click the Plot Strain History control 14 to see the effect of filtering for the selected sensor Indicator 17 will display the strain history Go back to the FFT PSD Analysis tab control 2 and repeat step vi through step ix to see the effect of filtering for all sensors Repeat the step 7 through step x until an appropriate cutoff frequency is determined This may require examining several data files one at a time By comparing the dominant frequencies of traffic plus noise induced and noise alone induced an appropriate cutoff frequency can be determined Once the FFT PSD analysis is completed and the desired cutoff frequency has been determined the second task can be performed to establish the appropriate filter parameters and to see if events peaks are properly identified The following steps are required to perform this task xxii xxiii xxiv XXV XXVI xxvii xxv
154. lus of elasticity and dimension of the deck 22 Define Frame Allows users to select among nine general section types I beam I beam tapered flanges I beam with angles T beam T beam tapered flanges channel channel tapered flanges P C shape and rectangular shape 23 Cross Section Display Graphic representation of a cross section selected in 22 It displays general information about the dimensions of the deck and beam components 24 Beam Dimension Frame Allows users to configure beam components 25 Sensor Location Frame Vertical locations at which section modulus will be computed for a composite or non composite member 726 Click to Compute Properties Command When pressed section properties will be computed and the results listed below will be displayed in 29 30 and 31 for non composite composite N and composite 3N sections respectively Note that section properties for a long term composite 3N section are computed and displayed in 31 for comparison purposes only and are not used in the analysis 27 OK Command When pressed e The results displayed in 29 or 30 will be copied into 13 14 and 15 depending upon the option selected in 20 e The program will close the Section Properties window and move back to a previous window Span Description window 19 28 Cancel Command When pressed the program will cancel the actions performed within the Section Properties wind
155. m Multiple Files VI Figure 2 13 Illustration of overall procedures involved in the field monitoring software Yes 4 MainDAQSI5 VI 34 pued yuo OV Cavumuiyasg jo JOYS p c MIIA 02 CTT DTI 0077 S Gee AOTT 0277 AUNE moti AST CTT u MATT Oury pue Ey ax a ur suts spend p peo send send BMD Wen CAN 2221 TIS M 8 euueu 9 jauueu p Jeuueuy Jeuueu Z TOTEM qoogujeis um sure Fg Gest I GUEDE 32301 mn pt JNO 9440200 kKHS 2 SE 2 725 DH 20 an dy WMHS y sags ums 34 agus p TT ong yum SATE 0067 27 11 aus ucrantoy d eette 390184 n eec D 21 emm iav 35 820 oz r V um penes epi avos iade HOVE atem Deren ee d temm cort penna Tm CO
156. m developed in this work and presented herein was developed to be an open and flexible SHM system that can be used to monitor under normal operating conditions typical girder bridges for overloading and changes in behavior e g from deterioration sudden events etc A reliable system of this type requires accurate analysis structural modeling and consideration of typical scenarios An overall schematic for the SHM system is illustrated in Figure 2 1 The SHM system can be principally grouped into two main components an office component and a field component The office component is basically a structural analysis software package that can be used to generate bridge specific thresholds The field component includes hardware and monitoring software which performs the data collection processing and evaluation The hardware system consists of sensors data acquisition equipment and an optional communication system backbone The field monitoring software was developed such that once started it will operate autonomously with minimal user interaction Detailed descriptions of each of the components and their implementation are presented in the following sections Section 2 1 describes various features included in the structural analysis software and highlights some of the theoretical methodologies used to develop it In Section 2 2 various elements of the field monitoring software are discussed along with a general background and summa
157. mensions Section Properties window for standard steel cross sections Section properties for standard steel can be computed in the window illustrated in Figure 2 6b This window is called when the Standard Steel option is selected in the Member Cross Section frame 9 In this window information on six classes of standard steel sections can be found A member can be selected with a mouse click Upon selected the member label will be highlighted in blue and the corresponding section properties will be displayed in the Beam Information frame 34 25 Section Properties window for Iowa P C cross sections The Section Properties window presented in Figure 2 6c appears if the Iowa option is selected in the Member Cross Section frame 79 Information on two types of Iowa P C sections can be found Upon selection the list box indicator 36 will display the members that are available and their basic properties will be displayed in the Beam Information frame 34 Section Properties window for AASHTO P C cross sections Section properties for AASHTO P C section can be computed in the window illustrated in Figure 2 6d This window is called if the AASHTO P C option is selected in the Member Cross Section frame 9 Information on four types of AASHTO P C sections can be found Upon selection of an option in the AASHTO P C frame 37 the list box indicator 38 will display the corresp
158. message will be sent to the recipients whose addresses are specified in the DAQ Inputs file note it requires an internet connection Each alarm message will be sent in the form of a text message that includes the date and time of the event sensor identification cause of event either overload or impact and the magnitude of the event in microstrain The information generated by Data Process VI will be temporarily stored within the sub program before it is written to a file Meanwhile raw strain records will be written to a new data file and the procedures within Data Process VI will be repeated every 10 minutes When the Data Process VI is notified six times 6 x 10 minutes 1 hour a notification will be sent from the Data Process VI to a 53 sub program Hour VI within which hourly data files will be created and saved in the 3 Data File Folder The procedures performed within sub programs Week VI Month VI and Year VI are very similar to the except that the number of times each sub program is notified is different and that the notifications to Week VI Month VI and Year VI are all sent from Day VI Once the 0815 is successfully started the data acquisition reduction evaluation and archiving processes will be completely autonomous and require no further user intervention unless the user desires to change input settings or restart the program To do this a user must stop the
159. mum Momert ftps and Syur Truck Position Miti 150 64 when P1 is 6l 59 M y 3950 when P1 is 112 Stain 124 when P1 is ot be Stain y 33 when ia oi 112 LU b When At a designated location option is selected Figure 2 9 continued 20 L View Data Results of BEC Analysis created at 12 3 2006 2 39 00 PM xf distance in feet from the left exterior support M Maximum positive moment in f kips at Maximum negative moment in ft kigs at X u Maximam positive strain in microstrain at X Maximum negative stain in microstrain at siy M uC 243 01 130 10 42 72 1 74 413 32 22 0 lt 71 63 31 1E 11N F9 130 23 130 23 72 37 51 83 731 93 40 82 13 62 39 32 5 02 30 73 106 23 123 8 a When In each span option is selected Figure 2 10 View Data Window 21 L View Data Results of BEC Analysis created at 12 13 2006 5 39 20 PM ft First axle position in feet from the left exterior support Moment ft kips Moment at a designated location when the first axle is at Strain microstrain Strain at a designated location when the first axle is atX xift Moment ft kips Strain microstrain 0 00 0 00 0 08 0 06 0 30 0 25 0 68 0 56 1 21 1 00 1 88 1 55 2 70 2 23 3 66 3 02 4 76 3 93 6 01 4 95 7 39 6 09 8 91 7 34 10 56 8 71 12 35 10 18 14 27 11 77 16 33 13 46 18 57 15 31 21 07 17 36 23
160. n is available for this column see Units This calurm 15 used for calbrating load cell or transducer using the Name Plate calibration method To n value select the Dox and enter number gester than 0 end less than 1000 fill option is avalable for this column see Unts This column used for cebbrating any sensor using the Shunt calibration method The value must equal the value of the shunt resisto ohms To change the value select the box and enter number greater then 2 aridless than 1000020 The shunt value must not exceed the valve entered as the maximam Dad The fi option is available tor this Used for catirabng any sensor using me Shunt calibration method The value refers to the bridge arm thet is shunzed during shunt calibration To chenge the value select the box and enter a number from ED to 1000 The fif option 15 evarteble for this column see Units Thies column is used for load cell or transducer using the Name Plate calibration method To change mis value select the box and enter number greater than 0 and less than 100000 The full rated load must be greater than the value entered for the ced for caloratbing amy sensor using any o change tha v sele Ihe bax and enter number greater than Candies hen 1000000 This value be cali taung any Sensor using any ation method The value entered 5 the value of the quiescent load on the sensor To change the value s
161. n the table indicator 720 where each row represents the settings for the sensor specified in the first column named Sensor xxx Repeat steps xiii through step xix until the filter parameters and the event detection thresholds have been established for all sensors xxxi Set the path 21 to which the filter parameters and event detection thresholds will be saved The default file name and directory is C SHM Folder Filter Paremeters txt xxxii Click the Create File for Filter Parameters control 22 to create a text file that contains the filter parameters and event detection thresholds for all sensors xxxiii Click the STOP control 23 to stop the program a FFT PSD plot display for the selected sensor b Strain record display for the selected sensor Figure B 2 Screen shots of 2 FFT PSD Analysis VI front panel c Filter parameters display B 6 Figure B 2 continued 3 Input VI shown in Fig B 3 Xxxiv XXXV XXXVI XXXVII xxxviii xli xlii Select the channels of a connected StrainBook 616 and if applicable a WBK16 expansion module to be activated 1 amp 2 More than one channel can be selected by Ctrl Mouse click Configure each channel 3 based on the type of strain sensor and its setting used Enter the device name in control 4 The device name used here must match what was used during the hardware
162. ng on the START control 10 Check the acquisition status in indicator 11 When the START control is pressed it searches the data acquisition instrument specified in control 1 One of the following situations will occur o The check mark on the status check box stays green and the indicators 12 13 14 and 15 will display real time data elapsed time beginning time at which data acquisition is initialized and current time of data acquisition respectively This indicates that the data acquisition instrument was found and all input parameters are correctly defined o The check mark on the status check box turns red and a message appears on the message box along with an error code This indicates that either the data acquisition instrument was not found or one or more input parameters are missing In order to resolve this error users must check either or both the hardware and IOtech software installation setup or and the input parameters before running the program again Once the data acquisition is completed click the STOP button 16 This will terminate the program 1 Preliminary DAQ vi ER Qoeate Toot wincow Heo 2 Microstraie e RON 9 ow IOWA STATE UNIVERSITY B R 06 ENGINEERING CENTER Fis Fath d Chat or Folter Cathraton Fie Data Fle Save th 25 mary Data Fower e Se
163. nt properties can be defined using controls 8 through 16 e The Member Cross Section frame 9 allows the user to define or select sections for a member with the material properties defined in the Beam Material frame 10 One of the convenient features in BEC Analysis is a section property Calculator 12 with which users can either directly input section properties of a member or have the program automatically compute the section properties of virtually any cross section Allowable shapes include user definable geometries common standard steel shapes Iowa P C shapes and AASHTO P C shapes Detailed description on these options will be discussed in Section 2 1 2 3 The text boxes in 13 14 and 15 display the moment of inertia 13 the section modulus 14 at the lower sensor location and the section modulus 15 at the upper sensor location for each segment in a member These values can be either manually entered by the user or computed with the Calculator 12 Note that the default sensor locations are set to be at the bottom of the beam lower sensor and the top of the beam upper sensor Note that these sensor locations can be changed in the Sensor Location frame 25 which can be found in the Section Properties window 19 The length of each segment in a member is defined in the Section Distance frame 16 Note that this frame will only be enabled if the Non Prismatic Member option is se
164. nts Electric shock or damage to equipment can result even under low voltage conditions Take ESD precautions packaging proper handling grounded wrist strap etc Use care to avoid touching board surfaces and onboard components Only handle boards by their edges or ORBs if applicable Ensure boards do not come into contact with foreign elements such a5 oils water and industrial particulate Be careful to avoid component damage while the Strain Book is open Always remove bridge completion headers CN 115 from the unit before soldering resistors in the headers To remove the cover plate you must first remove the top inward screw from each of the four mounting brackets The Cover Plate is Secured by 4 Screws 2 Screws per side 1 Remove the StrainBook from power and disconnect the unit from the host PC and from all extemally connected equipment prior to removing the cover As stated in the above CAUTION electric shock or damage to equipment can result even under low voltage conditions 2 Ensure you have taken proper ESD precautions proper handling grounded wrist strap ete 3 Remove the top inward screw from each of the four mounting brackets 2 screws per bracketed side 4 Carefully remove the cover 6 4 Bridge Configurations 529484 StrainBook 616 User s Manual Excitation Connection Remote sense inputs are provided for the excitation regulators The excitation voltage will be most accurate at points where rem
165. o Compute Properties OK Cancel Non Composite Composite Composite 3N TH IE 1 0 125737847222 4 29 6695322870 ft 4 20 1722305475 4 Stop 57436397865 1 3 Stop 26 7547127983 f3 Stop 11 8126706996 73 Sbot 53436454978 ft 3 Sbot 102625314149 Sbot 57999090394 73 d Section properties for AASHTO P C option Figure 2 6 continued 15 Loads lowa Legal Loads HS 20 C Type3 C Type 4 C Type 352 C Type 3828 ie loa Legal Loads HS 20 5 Truck Trein 33 0 Detine Number of Ades C Type 353 C H 20 2 axles C HS 20 3 exes Distribution Factor Impact Allowance IM p 48 EI bn Ep s Fg SU e n a Axle Load P Distance between Axes LP ff Figure 2 7 Load window 16 W Analysis Maximums and Locations Find the Maximum Results Truck moving at every ft 5c In each span 544 Ata designated location 30 55 ft from the left exterior support Aun Analysis 57 Maximum Moment ft kips and Strain microstrain Truck Position M whenPliset 59 M when P1 is at 112 Strain whenPlisat 59 Strain when P1 is at 112 a At a designated location option Figure 2 8 Analysis window 17 Analysis Maximums and Locations Find the Maximum Results Truck moving at every E No of Analysis Points Beam 10 65
166. o the firstaxle DOSICIOB erret por maps e ao bae 13 Figure E 13 Moments and strain due to HS 20 truck train lane loading at the sensor locations with respect to the first axle positions t ed ee fume tbe evi dius 14 viii LIST OF TABLES Table 3 1 Summary of maximum moments ft kips and strains microstrain and corresponding first axle positions b1 ft for Sensors 5 and 8 Table 3 2 Summary of maximum moments ft kips and strains microstrain and corresponding first axle positions b1 ft for Sensors 1 and 4 Table 3 3 Filter parameters and peak detection thresholds Table 3 4 Overall summary of 30 day monitoring essere Table 3 5 Statistical Trends daily maximum average in microstrain Table 3 6 Number of identified events bin width 20 microstrain sass Table B 1 Description of selected controls and indicators in 1 Preliminary DAQ VI Table B 2 Description of selected controls and indicators in 2 FFT PSD Analysis VI Table B 3 Description of selected controls and indicators in 3 Input VI sss Table B 4 Description of selected controls and indicators in 4 MainDAQ515 VI Table B 5 Description of selected controls and indicators in 5 View Strain History VI Table B 6 Description of selected controls and indicators in
167. onding members that are available A member can be selected with a mouse click If selected its label will be highlighted in blue and the corresponding section properties for the selected member will be displayed in 34 2 1 2 4 Load Window Once a model bridge has been constructed using the above described windows loads can be defined in the form of either a series of point loads that simulate trucks or uniformly distributed loads with one or two point loads that simulate lane loads The Load window 39 shown in Figure 2 7 allows the user to configure live loads that will be applied to the bridge The software provides options for Iowa legal loads H 20 and HS 20 trucks truck train as well as user definable live loads In addition a distribution factor DF and impact allowance IM can be defined When the user chooses the Iowa Legal Loads HS 20 option 40 the Iowa Legal Loads HS 20 frame 46 will be enabled which allows the user to select one of the listed trucks When an option is selected in 46 the information of the selected truck axle weight wheel line load distance between each axle and its graphic representation will be displayed in 49 50 and 51 respectively A truck train loading will be applied if the Truck Train option 41 is selected Selecting this option will enable a text box control where a default magnitude for a uniformly distributed load will be displayed 43 and the Apply W on
168. or data transfer and storage System requirements and necessary procedures on IOtech software installation and hardware system setup as well as the sensor calibration process are provided in Appendix C The user must create a directory entitled SHM Folder that contains the following four folders 1 Raw Data 2 Data Process 3 Data File Folder and Preliminary Data Folder In the following sections overall procedures involved in running each program are described In addition step by step instructions on how to run each component are provided in Appendix B 2 2 3 Preliminary Data Acquisition and Analysis The first applications of the field monitoring software suite preliminary data acquisition and analysis are used to collect and establish information needed by other programs Specifically this process is intended to establish parameters that will be used in data processing for reducing noise and detecting events 33 Initial Setup IOtech software installation Hardware system setup Sensor calibration SHM main directory creation 1 Preliminary DAQ VI 10 minute data available Sample data collected 5 View Strain History VI Yes 2 FFT PSD Analysis VI Hourly data file s Parameters available idealized 3 Inputs VI Input file created No Daily weekly monthly yearly file s available 7 Create Report From Single File VI amp Create Report Fro
169. or the Define option 42 enter the number of axles 44 the axle weights 49 and the distance between each axle 50 The indicator 51 will be disabled if a live load has a single axle xvi Enter distribution factor 47 and impact allowance 48 that will be used in the analysis xvii Click Next 4 to open the Analysis window 52 shown in Fig A 6 A 11 P iaat fe n2 Bo wear Pl uel nz Find the Maximum Results 6 ineach span No of Analysis Points Boan 65 C Ata designated location 5 fun Analysis Strain Span MO Strain Sein 2 MO Swain o 66 9 poz Stein Svane b each span option Figure A 6 Analysis window xviii Choose an appropriate option for viewing results 53 or 54 e For the In Each Span option enter the increment 56 at which a live load will move along the model bridge Enter the number of analysis points that will be used in the analysis A 12 xix XX xxii xxiii xxiv XXV xxvi xxvii xxvii For the At a Designated Location option enter the increment 56 Click the Run Analysis command button 57 to run the program While running its status will be displayed in the progress bar indicator 63 If the analysis is successfully completed
170. ot affect the identification of traffic events peaks while eliminating those events induced by free T vibration of the bridge Examples of strain history plots that illustrate the effect of setting the filter parameters and the peak detection thresholds are presented in Figure 3 10 Figures 3 10a and 3 10b illustrate the noise induced strain history plots generated from a 3 minute sample data Note strain history before filtering is in green and after filtering is in gray By comparing these two plots it is obvious that the use of the cutoff frequency at 2 8 Hz minimizes most of the noise Examples of the strain history plots that illustrate the effect of using different peak detection thresholds are presented in Figures 3 10c through 10e As shown in Figures 3 10c through 3 10e the use of 2 microstrain resulted in numerous peaks being detected during free vibration However setting the threshold to 5 microstrain minimized detection of the free vibration portion of the record After the filter parameters and peak detection thresholds were determined they were saved to a text file in the SHM main directory so that it can be used during normal monitoring The finalized filter parameters and peak detection thresholds for each sensor are presented in Table 3 3 Table 3 3 Filter parameters and peak detection thresholds Peak Detection Thresholds 2 Sensor Cutoff Frequency Hz Filter Order Ripple dB microstrain Positive Nega
171. ote sense lines are connected preferably at the bridge this is often referred to as 6 wire connection Long cables will reduce the voltage at the bridge due to current flow and wire resistance if remote sense is not used If the 6 wire approach is not used the remote sense inputs must be jumpered to the excitation outputs at the Input connector Internal resistors are also connected where the jumpers would be located to prevent circuit discontinuities These 1 MQ resistors not suitable for high accuracy excitation voltage regulation 3 wire quarter hridge configurations do not benefit from external remote sense connections The lead resistance is actually a balanced part of the bridge If the remote sense input is connected to the input on quarter bridge the voltage is regulated across the bridge completion resistor This results in a constant current linearized quarter bridge otherwise quarter bridges are not perfectly linear Shunt Calibration Resistors SirainBook provides three physical locations for intemal shunt calibration resistors for cach channel Each shunt resistor is switched in from the EXCITATION to the IN of the Instrumentation Amp by a FET switch to create a repeatable bridge imbalance Internal resistance of the circuit is about 1 the exact amount is automatically accounted for in the software The software also allows selection of the three shunt resistors B D F An intemal inversion s
172. other programs The second group of tools controls the main data acquisition and the organization of the collected data During this process collected data are temporarily stored into designed segments and then internally passed through a series of data reduction programs in such a way as to allow the acquisition program to operate in real time while the processing programs operate in the background These collected data are evaluated reduced written to a data file and archived all within the local host PC The results from the second group are a series of data files each of which contains summarized information about the bridge performance The third group of the field monitoring software is used for generating and viewing summarized reports During software development significant effort was taken to ease and minimize user interaction This was accomplished by utilizing a series of GUI for each of operation Each program was designed to provide users with immediate feedback A total of eight programs were created as are listed below e 1 Preliminary DAQ VI 1 Preliminary Data Acquisition 2FFT PSD Analysis VI and Analysis e 3Input VI 4MainDAQSIS VI 2 Main Data Acquisition and Processing e 5 View Strain History VI 6 View Hourly File VI e 7 Create Report from single file VI e 8 Create Report from multiple files VI 3 Report Generation The first two programs 1 Preliminary DAQ VI and 2 FFT PSD Analysis VI are
173. ow and move back to a previous window Span Description window 19 29 Non Composite Frame Displays results for a non composite section 30 Composite N Frame Displays results for a short term composite section 31 Composite 3N Frame Displays results for a long term composite section 32 Standard Steel Option Provides 6 options of standard steel section types W shape S shape HP shape channel and MC channel 33 Standard Steel List Box Lists standard steel section types depending upon the option selected in 32 and allows the user to select a member with a mouse click If selected its label will be highlighted in blue and corresponding section properties for the selected A 2 member will be displayed in 34 34 Beam Information Frame Displays section properties of a selected member 35 Iowa P C Option Provides 2 options of Iowa P C types LX and Bulb Tees 36 Iowa P C List Box Lists Iowa P C section types depending on the option selected in 35 and allows the user to select a member with a mouse click If selected its label will be highlighted in blue and corresponding section properties for the selected member will be displayed in 34 37 AASHTO P C Option Provides four options of AASHTO P C section types Slab Beams Box Beams I Beams and Bulb Tees 38 AASHTO P C List Box Lists AASHTO P C section types depending on the option selected in 37 and allows the user to se
174. performance summaries 1 Open the Daq Configuration Applet a Open the Control Panel by navigating from the Windows Desktop as follows Start Menu Settings gt Control Panel b From the Control Panel double click the Dag Configuration icon 2 Add the first level device to the list of installed devices The first level device is the device that vill be connected directly to the Ethernet via a host computer s Ethernet jack or a jack on network hub The StrainBook 616 is an example of a first level device a Select the Computer image the Device Inventory configuration tree following figure b Click the lt Add Device gt button The Select Device Type box will appear Select StrainBook 616 from the list of devices as applicable d Click the lt OK gt button The Properties box will appear for the selected device e lype Using Configuration Device Inventory amp Select Device Type to Add a Device StreinBookw 16 User s Manual Setup and Connecting tothe Ethemet 5 11 C 12 3 Set the properties of the first level device In this step you will set the device properties according to one of the following two methods depending on whether you have a Dedicated Network oc a LAN with DHCP Server Network Users of Dedicated Networks follow these 2 steps a Enter the Serial Number of the first level device StrainBook 616 In the following screen shots the Serial Number is
175. program by pressing the STOP control 6 set the Reset control LED option in 77 to true bright green and re run the program by pressing the control 9 These actions will result in autonomously creating an Old Data File Folder to which previously archived data files will be moved This will allow the user to keep the old data files saved in a different directory so that they can be retrieved if necessary When an Old Data File Folder is created the time at which the folder is created will be included in the folder name The naming convention used here is similar to those discussed in Section 2 2 3 1 except that in this case the letters is replaced with Old Data File Folder As described the outcome of 4 MainDAQS15 VI is data files created on a timely basis hourly daily weekly monthly and yearly that are archived in the 3 Data File Folder in the main directory In writing and creating each data file the binary format was utilized as it takes less memory and does not require slow sequential searching of data content The data files created here will be used for the application of viewing and generating reports which are described in Section 2 2 5 2 2 4 3 Accessing Last 10 Minute Data As mentioned previously strain records stored in the Lastl10MinData file will be updated every 10 minutes to allow a user to view what has recently been collected 5 View Strain History VI a
176. r viewing locations and magnitudes of maximum moments and strains in each span 54 At a Designated Location Option Option for viewing magnitudes of maximum moments and strains at a specified location 55 X Control Location at which the maximum moments and strains will be generated upon completion of analysis This control will be enabled when option 54 is selected 56 Truck Moving At Every Control Incremental distance that each axle will move along the model bridge starting from the left exterior support The smaller the increment the longer the processing time will be 1 inversely proportional to the increment used but the greater the accuracy 57 Run Analysis Command When pressed the analysis will be initialized and the progress can be seen on the progress bar 63 When the analysis is successfully completed a prompt dialog box with Analysis Complete will appear 58 M Indicator Maximum positive moment in ft kips at the location specified in 55 or 67 59 M Indicator Maximum negative moment in ft kips at the location specified in 55 or 67 60 Strain Indicator Maximum positive strain in microstrain at the location specified in 55 or 67 61 Strain Indicator Maximum negative strain in microstrain at the location specified in 55 or 67 62 Truck Position Indicator Location of P1 first axle on a model bridge when corresponding results are generated The location o
177. re A 7 Print Maximums Window A 14 b When Ata designated location option is selected Figure A 8 View Data Window A 15 a When In each span option is selected b When At a designated location option is selected Figure A 9 Plot Window A 16 APPENDIX B Principle Procedures in Running the Field Monitoring Software BL T Preliminary 127 B2 2 4E ET PSD Analysts VE 128 B3 3 Input o t RH 132 B4 4 DAOSIS VI 135 B5 5 View Strain History VIE ctii isi KR GRE ins 137 View Hourly File VI ao esce see eee 138 B7 7 Create Report From Single File VI and 8 Create Report From Multiple Files VI YFE o A PIA 139 Description on Controls and Indicators Table B 1 Description of selected controls and indicators 1 Preliminary DAQ VI 143 Table B 2 Description of selected controls and indicators in 2 FFT PSD Analysis VI 143 Table B 3 Description of selected controls and indicators in 3 Input VI 145 Table B 4 Description of selected controls and indicators in 4 MainDAQS15 VI 146 Table B 5 Description of selected controls and indicators in 5 View Strain History VI
178. routine stiffness method except that the member stiffness matrix and the fixed end moments have been modified to account for the potential variation in member cross sections The general matrix formulation for the member end forces can therefore be expressed as below MA MF KS D 2 1 where MA Member end force vector MF Fixed end moment vector KS Unit displacement stiffness matrix D Nodal displacement vector D S Z1 Z Nodal force vector 5 Stiffness matrix The general theories and methodologies briefly outlined in this section have been incorporated into a computer program BEC Analysis which makes time consuming analyses relatively simple All that is required to complete an analysis is to define the important bridge parameters The following section presents a summary of BEC Analysis 2 1 2 Features and Components of BEC Analysis BEC Analysis runs on a Windows platform personal computer PC and consists of three modules pre processor analysis and post processor Each module was respectively developed to perform a certain task such as model generation analysis and result viewing These three modules can be further categorized into six sub groups 1 Bridge Information windows 2 Span Description windows 3 Load window 4 Run Analysis window 5 Print View Plot windows The pre processor groups 1 2 and 3 are used for data input modeling and on screen graphic display The analysis mod
179. rs in 6 View Hourly File VI Control or Indicator Description 1 Data File Folder Control Directory into which the data files created during the main data acquisition are archived 2 Monitoring Period Option for selecting a data file to be plotted Control 3 View Data In Excel LED option that allows users to view the data files in Spreadsheet Control Excel Worksheet The default is false dark green If set to true bright green information contained in a selected file will be displayed in Excel Worksheet 4 Histogram Variables Allows users to change the format of the histogram plot Controls 5 Click to View Hour File When pressed event history and event histogram will be Control displayed in the graph indicator 77 for each sensor Also an Excel Spreadsheet containing information processed by the program will be created if the LED option 3 is set to true 6 Plotting Progress Provides the status of the plotting progress If being Indicator processed Wait is shown and turns red If completed Ready Done is shown and turns bright green 7 Graph Indicator Displays event history and event histogram for each sensor 8 Monitoring Period of Displays the monitoring duration in date and time for a Selected File Indicator selected file 9 Alarm Message Displays alarm messages recorded during the monitoring Indicator period displayed in indicator 8 10 Stop Control When pressed the program will
180. ry of the methodologies employed in the development Finally Section 2 3 discusses the hardware components that include sensors data acquisition and communication 2 1 Structural Analysis Software A Windows based two dimensional live load structural analysis program BEC Analysis was created to simplify determination of some of the bridge specific SHM system parameters BEC Analysis is capable of analyzing a bridge beam or girder with various boundary conditions and member geometries under various moving load conditions One unique feature of BEC Analysis is that it allows users to easily determine maximum results maximum moment and strain at any location along the length of a model bridge In addition it contains many convenient features which allow relatively quick analysis of a bridge In general one may use BEC Analysis for 1 analyzing beams or girders under moving loads 2 computing absolute maximums in each span or at a desired location and 3 generating envelopes of maximum moments and strains The following summarizes some of the features that are included in BEC Analysis e Text fields and click to select options used to define bridge parameters e Input defaults that will help novice users e Library of various member cross section properties e Calculator that computes section properties of virtually any member cross section e Capable of modeling non prismatic members e Run multiple analyses without exiting the program
181. s 16 Create and Save Input When pressed an input file will be created and saved in File Control the SHM Folder main directory C SHM Folder 17 Stop Control When pressed the program will stop B 19 Table B 4 Description of selected controls and indicators 4 MainDAQ 815 VI Control or Indicator Description 1 Acquisition Status Error dialog box that displays a numeric error code and a Indicator corresponding error message upon occurrence of error error red no error green in the status check box 2 Real Time Raw Data Displays real time raw strain data Indicator 3 Time Indicators Displays 1 date and time at which data acquisition 1s initialized 2 current date and time 3 count of elapsed hour day week month and year 4 Network Status Error dialog box that displays a numeric error code and a Indicator corresponding error message upon occurrence of error error red no error green in the status check box 5 Disc Memory Space Displays a total used and free available disc and Indicators Bytes physical memory space in the local host PC 6 Stop Control When pressed the program will be stopped 7 Reset Control A LED option that will initialize new acquisition The default is false dark green If set to true bright green upon program execution a directory Old Data File Folder will be created and the data files saved up to that point will be moved to this
182. s number of bins and maximum and minimum bins for both positive and negative events e Press the Click to View Hour File control 5 to execute the program event history and histogram monitoring period and alarm messages will be displayed in the indicators 6 7 and 8 respectively The event history and histogram for each sensor can be accessed by selecting the tabs designated for each sensor e Stop the program by pressing STOP control 9 2 2 5 2 Creating Reports Accessing Daily Weekly Monthly or Yearly Created Data Files Three sets of information are generated for each sensor in a performance report event history event histogram and statistical trends The event history graph presents the numerical count of identified events along the x axis with their magnitudes in microstrain on 55 the y axis The histogram presents the count of events in each bin whose size can be defined by users The statistical trends graph displays the absolute maximum event the average event and a trend line for the averages over the monitoring period The following procedures are involved in running 7 Create Report From Single File VI and 8 Create Report From Multiple Files VI Note that the numberings for the controls and indicators used on the front panels of these two programs are the same as shown in Figures 2 20 and 2 21 Therefore they are treated together in the following description e Select the directory 1 in w
183. s with respect to the first axle position o uas eats ccs eres isa ge toda etate t ve oA ed ei 5 Figure E 5 Moments and strain due to Iowa legal truck Type 3 3 at the sensor locations with respect to the first axle posttlOn c osos erar e rupe be d ess 6 Figure E 6 Moments and strain due to Iowa legal truck Type 3S3 at the sensor locations with respect to the first axle position Root tere etit el eet 7 Figure E 7 Moments and strain due to H 20 truck 2 axles at the sensor locations with respect tO the fitst axle POSTION Ee eo Opa Od LR c keit 8 Figure E 8 Moments and strain due to HS 20 truck 3 axles 14 ft at the sensor locations with respect to the first axle ere en tee E Pd debe REI i qb gas 9 Figure E 9 Moments and strain due to HS 20 truck 3 axles 15 ft at the sensor locations with respect to the first axle position Loses ceto etr o it e Reb uai 10 Figure E 10 Moments and strain due to HS 20 truck 3 axles 20 ft at the sensor locations with respect to the first axle position cor te taa s 11 Figure E 11 Moments and strain due to HS 20 truck 3 axles 25 ft at the sensor locations with respect to the firstaxle DOSICIO en te eid ruo o qe SASS 12 Figure E 12 Moments and strain due to HS 20 truck 3 axles 30 ft at the sensor locations with tespeet t
184. s in structural behavior identification of damage and deterioration and for tracking usage These specific needs were established to give owners tools to better manage bridge assets and were accomplished by completing three distinct work tasks as follows e Development of live load structural analysis software e Development of field data collection and analysis software that integrates with select data acquisition hardware e Demonstration of the developed SHM system The product of this work is a turnkey SHM system that consists of hardware and software components The hardware consists of off the shelf components that have been integrated to work together Two software packages were also developed that allow for effective system use First a structural analysis package was developed that allows for bridge specific system configuration Second data collection analysis reporting package was developed that operates without user intervention to monitor for the above mentioned reasons 1 3 Report Content This report is divided into four chapters A detailed description of the system development and its components are given in Chapter 2 Chapter 3 presents the demonstration of the SHM system and the associated performance evaluation General summary and conclusive discussions are provided in Chapter 4 In addition significant user manual materials are provided in the report appendices 2 STRUCTURAL HEALTH MONITORING SYSTEM The syste
185. s option allows users to change five variables number of bins and maximum and minimum bins for positive and negative events Press the Click to Create Report control 7 to execute the program As soon as the program is executed the status indicator 78 will turn red indicating that the program is in progress Upon completion the indicator will turn bright green and the following results will be generated o results displayed on the front panel for immediate view i the time at which the data acquisition was initialized 9 ii the monitoring period 10 ii alarm messages recorded during the monitoring period 11 iv event history event histogram and statistical trends for each sensor 12 13 and 714 respectively see Note 2 below for more detail o Excel Worksheet hard copy and or PDF file depending upon the selected options 3 4 and 5 lxx Stop the program by pressing STOP control 15 Note 1 As can be seen in Figs D 7 and D 8 controls and indicators used on the front panels of each program are exactly the same with the exception of the Monitoring Period control 2 7 Create Report From Single File VI is designed to access one data file at a time while 8 Create Report From Multiple Files VI allows users to open multiple files at once Consequently different options in control 2 for selecting data files were utilized For 7 Create Report From Single File VI users can choose a
186. s shown in Figure 2 18 was developed to allow a user to easily view these data The following procedures are involved in running the program e Select the data file 1 that contains collected strain records e Set the path 2 to the filter parameters file that contains the event detection thresholds and filter parameters that were previously established e Enter the sample rate 3 that was used during data acquisition e Press the Plot Strain History control button 4 to execute the program When this button is pressed the status indicator 5 will turn red indicating that the operation is in progress Upon completion the indicator will turn bright green and the strain history for each sensor will be displayed on the graph indicator 6 The strain history for each sensor can be accessed by selecting the tabs designated for each sensor e Stop the program by pressing STOP button control 7 54 2 2 5 Report Generation Once the data files are created and archived in the 3 Data File Folder directory and or sent to users via email these data files can be accessed and reports generated by executing 6 View Hourly File VI 7 Create Report From Single File VI and 8 Create Report From Multiple Files VI When the SHM system is operated for a long time numerous data files will be archived in the 3 Data File Folder directory Although the naming convention utilized would ease identifying each data file it may still tak
187. s that while 1 Preliminary DAQ VI writes and saves data files to the Sample Data File folder in the main directory 4 MainDAQ615 VI uses three folders within the main directory 1 Raw Data 2 Data Process and 3 Data File Folder Raw strain records for each sensor are collected and written to a data file in the 1 Raw Data folder directory with the same format discussed in Section 2 2 3 1 Every 10 minutes this data file will be closed saved and moved to the 2 Data Process folder for data processing At that point the strain records are filtered and processed Following the data reduction process only the extracted strain records events will be passed on to the next phase of data evaluation Before all other raw strain records are discarded a data file LastlOMinData that contains the raw strain record for 10 minutes will be created in the main directory to allow the user to access the last 10 minutes of data Note that while the information within the file is updated every time a sub program Data Process VI is called and new strain records for 10 minutes are saved the name of the file will not change Accessing this Last10MinData will be discussed subsequently During the data reduction and evaluation processes each peak or event will be detected and alarm messages will be recorded Upon an occurrence of an alarm event a sub program SMTP Email Send Message VI will be called and a warning
188. se click 79 to be sent via email LED options Given that the internet connection is available if users desire to receive daily data files only for example the LED option for Daily Data must be selected bright green with a mouse click and other options must remain unselected dark green Six options are available as follows a Hourly Data allows users to receive hourly generated reduced data files each of which contains event history in the preceding hour b Daily Data allows users to receive daily generated data files each of which contains event history in a day c Weekly Data allows users to receive weekly generated data files each of which contains event history in the preceding week d Monthly Data allows users to receive monthly generated data files each of which contains event history in the preceding month e Yearly Data allows users to receive yearly generated data files each of which contains event history in the preceding year f Alarm Message allows users to receive a text message of an alarm event upon occurrence Enter email information that the reduced data files are sent from to 10 and set Check if email inputs are entered LED option to true bright green with a mouse click Three pieces of information are required a Return address email address of the file and or message sender b Mail server the name or IP address of an SMTP server c Recipients email addresses of the file and or m
189. sed to determine a slope in a strain record 2 2 1 2 Compensation of Temperature Effects and Noise Minimization Collecting reliable strain data requires attention to the unique characteristics of bridges and the surrounding environment Typically measured strain data from bridges contains components that can be categorized into two general parts traffic induced strains and other unwanted elements such as changes in strain induced by temperature variations and noise The useful information for the methodology used here are those collected data resulting ambient traffic only Therefore eliminating or minimizing the unwanted elements is imperative It is widely known that temperature related effects are one of the most common issues with measured strain data Various attempts have been made by manufacturers to minimize the sensitivity to temperature through selection of strain gauge materials Although adjusted strain gauges are known to reduce some level of thermal issues they do not totally 29 eliminate the effect The approach for compensating the temperature variations used here is based upon the idea that thermal expansion and contraction are very slow in comparison to changes associated with live loads Therefore one may assume that the change in strain due to temperature variations within a short period of time is insignificant With this consideration in mind it was decided that the strains be processed in small segments so tha
190. settings Select a Device Start Menu gt Programs gt Strain Book 616 Software gt DaqIPConfig Device Properties 2 Open the DagiPConfig Applet Humber d Click on the DaqIPCoafig selection to open the applet Adie OTT tandi un 3 Selectthe device that is to have the address change ar adden Note In the above figure there is only one device to select ie StrainBook 616 Iz E 4 Setthe internet protocol TCP IP settings to be Mw 25 0 0 9 compatible with host computer 0 0 0 0 a Select the radio button labeled Use the following IP address b Enter the new internet protocol settings If needed consult your network administrator for acceptable numbers Click the lt OK gt button 5 Reboot the device The new IP address will not take affect until the device has been powered off then powered back on 6 Repeat steps 3 4 and 5 for other devices in the system After configuring the network settings for all devices proceed to Step 7 10 Setup end Connecting to the Ethemet StrainGoows16 Users Manual STEP 7 Configure and test the System using the Daq Configuration App The Dag Configurstion applet is located in the Windows Control Panel Tt allows you to add or remove a device and change configuration settings The mcluded test utility provides feedback on the validity of current configuration settings as well as
191. sition and analysis is a task that assists in reducing noise and detecting events so that only the pertinent strain information is obtained It involves establishing the parameters that will be used during the data processing and evaluation processes that occur in other programs The second group of programs controls the main data acquisition and the organization of the collected data and passes it to the processing components During this process collected data will be temporarily stored into designed segments and then internally passed through a series of data reduction programs in such a way as to allow the acquisition program to operate in real time while the processing programs operate in the background These collected data are evaluated reduced written to a data file and archived all within the local host PC The results from the second group are a series of data files generated on a timely basis each of which contains summarized information about the bridge performance The third group of the field monitoring software is used for immediate viewing of summarized information and for generating reports Once the development of the SHM system was completed the system was tested and implemented on a highway bridge to demonstrate and verify its general usage The bridge selected for demonstrating the use of the developed SHM system is the 320 ft x 30 ft three span continuous welded steel girder bridge The bridge is located in central Iowa in Story
192. span 2 000 Moment Strain microstrain West Pier 1500 East Pier 1000 9 500 0 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 6 Moments and strain due to Iowa legal truck Type 3S3 at the sensor locations with respect to the first axle position E 7 2000 Moment ft kips Strain microstrain West Pier 1500 1000 m 2 500 0 500 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2000 Moment ft kips Strain microstrain West Pier 1500 East Pier 0 5 9 500 o 2 0 T T 50 350 400 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E 7 Moments and strain due to H 20 truck 2 axles at the sensor locations with respect to the first axle position E 8 Moment or Strain 2000 Moment ft kips Strain microstrain West Pier 1500 4 400 1000 First Axle Position ft a Sensors 1 and 4 in the center span 2 4 Moment ft kips Strain microstrain West Pier 1500 1000 B 2 500 c o E gt 0 350 400 500 1000 First Axle Position ft b Sensors 5 and 8 in the west end span Figure E
193. span as illustrated in Figure 2 8b Note that the location X at which the maximum is generated and the first axle position b1 are symbolically displayed in the graphic indicator 51 in the Load window 39 In addition to the absolute maximum results discussed above BEC Analysis can also generate moments and strains with respect to truck position moment and strain vs truck position or envelopes of maximums The results of moment and strain vs truck position analysis or envelopes can be accessed in the View Data window 74 and also in the Plot window 78 which will be discussed subsequently 2 1 2 6 Print Maximums Window The Print Maximums window shown in Figure 2 9 allows the users to print a hard copy of the absolute maximum results displayed in the Analysis window The specific results displayed will be based upon the options selected in the Find the Maximum Results frame in the Analysis window 53 2 1 2 7 View Data Window As mentioned in Section 2 1 2 5 moment and strain vs truck position analysis results can also be generated during the analysis The View Data window 74 allows the user to access the specific numerical results As illustrated in Figure 2 10 the data display box shows the maximum moments and strains in each span Note that the left column X ft represents the distance along the bridge for envelopes of maximums as shown in Figure 2
194. stop Table B 7 Description of selected controls and indicators in 7 Create Report From Single File VI and 8 Create Report From Multiple Files VI Control or Indicator Description 1 Data File Folder Control Directory into which data files created during the main data acquisition are archived 2 Monitoring Period Options for selecting data file s from which monitoring Control results are to be displayed and reports are to be generated 3 View Data In Excel LED option that allows users to view the data in Excel Spreadsheet Control Worksheet The default is false dark green If set to true bright green information contained in a selected file will be displayed in Excel Worksheet 4 Print Option Controls Options for printing the results in hardcopy and or PDF false dark green true bright green 5 Report Contents Options for selecting contents to be included in the Controls report false dark green true bright green 6 Histogram Variables Allows users to change the format of histogram plot B 21 Controls 7 Click to Create Report When pressed the event history the event histogram and Control the statistical trends will be displayed for each sensor in the graph indicators under Event History 12 Event Histogram 13 and Statistical Trends 14 tabs respectively Also a report and an Excel Spreadsheet cont
195. t the temperature effects on each set of measured strains are minimal To this end the field monitoring software was developed to process measured strain segments every 10 minutes Minimizing noise in measurement systems is important as it can present a serious problem The typical environment surrounding a bridge may contain abundant sources of noise In general high frequency noise is normally induced by radio signals while electronic equipment generates noise in almost all frequency ranges Although completely preventing the occurrence of noise would be the ideal situation it is seldom practical Fortunately the use of simple techniques such as appropriate grounding techniques shielded and twisted wires etc can control some level of noise However they do not eliminate noise completely One solution to further minimize noise is to identify and block the source of noise by use of filtering The use of filtering allows users to remove specific components that are not of interest Measured live load strains may have content across the entire frequency spectrum However the most important elements are contained in a relatively well defined frequency range In order to define where the desired strain data falls and or where the noise falls a Fast Fourier Transform FFT analysis can be utilized A FFT analysis allows users to view the frequency content of measured strain data Then one can choose an appropriate filter technique to extract the da
196. t can be found in Figures 2 20 and 2 21 while examples of graphical representation of an event histogram and statistical trends are presented in Figure 2 24 The formats used to display event history and event histogram are the same for both programs Also the format used to display statistical trends in 8 Create Report From Multiple Files VI is the same However the format of the graph indicator for displaying statistical trends in 7 Create Report From Single File VI can change depending on the tabs or pages selected in the Monitoring Period control 2 in Figure 2 20 If users select a monitoring period in the Daily tab the graph indicator will display statistical trends of each hour for 24 hours as shown in Figure 2 24b On the other hand if users choose a monitoring period in Weekly Monthly or Yearly tabs it will display statistical trends of each day for user specified monitoring periods For example if a monitoring period is selected in the Weekly tab on the front panel of 7 Create Report From Single File VI it will access one of the weekly created data files each of which contains collected information for seven days Therefore it will display statistical trends of each day for 7 days as shown in Figure 2 24c 57 c Monthly data file d Yearly data file Figure 2 22 Data file selection option for 7 Create Report From Single File VI a Up to date b Day i to Day 0 c
197. ta of interest Traffic induced strains in general have frequency contents that are lower than those of most other sources Applying a low pass digital filer therefore can modify frequency contents of strain records by only allowing frequencies that are lower than a specified cutoff frequency Previous work by the research team has shown that the Chebyshev filter effectively minimizes peak detection error with a relatively fast processing speed Thus the Chebyshev low pass filter was utilized for minimizing noise in the field monitoring software 2 2 1 3 Data Acquisition and Storage While a slow speed monitoring strategy may be suitable for monitoring displacements and deformations a high speed data acquisition is needed for capturing events that occur in a short time window such as maximum traffic induced strains large amplitude vibrations and behavior caused by a vehicle collision Therefore it was decided that the data sampling rate should be user selectable to provide more flexibility in the use of the software With this option available it is thought that the software can be used to monitor bridges built for high speed e g highway bridges as well as low speed traffic e g local bridges For a long term SHM system data sets that are collected over extended periods of time can cause problems as the size of the generated files can be quite large Managing a large data volume can be problematic since significant effort can be req
198. tage insures correct polarity during the shunt calibration process which arm is shunted is therefore irrelevant Header positions Rb Rd Rf correspond to the software shunt resistor selections of B D F For any balanced bridge a resistance value can be placed in parallel with one element to create predictable imbalance and output voltage This shunt resistance value can be calculated by the following equation where is the differential output voltage of the gage Example Rum 7 V tarttation 4 0 5 Raus 350 10 4 0 020 0 5 43 5730 Be careful to avoid component damage while Strain Book enclosure is open Always remove bridge completion headers adapter plugs from the unit before soldering resistors in the headers Solder resistor lead p Configuring the Bridge Completion Resistor Modules Foe each channel the imo fork board has 2 8 resistor socket with rows designated A through H The removable adapter plugs are included for soldering in the resistors Additional adapter plugs available for convenient changeover of alternate configurations Resistor Ra is located nearest the front panel Half bridge completion resistors consist of Rg and Rh o Quarter bridge completion resistors consist of Ra Rc and Re o Shunt resistors consist of Rb Rd and Rf Inserting resistors directly into the socket makes an unreliable connection and is not recommended R
199. the edge of its CN 115 header 60 Bndge Configurations 6 Users Manual 20 2 a The three wire quarter bridge has only one strain variable element and requires three bridge completion resistors BCRs The mtemal half bridge may be any two matched values but the remaining resistor must match the external quarter bridge value precisely Three of these values may be installed simultaneously when connected as shown below the connector pins determine which resistor 1s used With all three values installed WBK16 can accommodate al three quarter bridge values without changing the internal resistors CN 115 Header roommor A 120 ohm resistor and its corresponding shunt value may be installed as shown Three Wire Quarter Bridge Using 126 Om nominal B Sumt Resistor Sense Exctation CN 115 Header A 35U ohm resistor and its corresponding shunt value may be installed as shown Tove Vee Quarter Bridge Using RC 350 Ohm nominal D Shunt Resistor CN 115 Hondar 1000 ohm or other value resistor and its corresponding shunt value may be installed as shown Veve Ware Quarter Bridge Using RE 1 KOlwe nominal F Stent Resistor 6 10 Bridge Configurations StrainBook 616 User s Manual C 21 CA 1 089 Male Unterminat
200. the sensor calibration process by setting the LED option to true bright green and by assigning the calibration file path Designate the folder directory in which raw strain data file are to be written and saved 12 The default is C SHM FolderM Raw Data This is one of the sub directories created during the initial setup Designate the folder directory to which the raw data are moved for data reduction and evaluation 13 The default is CASHM Folder Data Process This is one of the sub directories created during the initial setup Designate the folder directory in which all the reduced data files Hourly Daily Weekly Monthly and Yearly Data files will be saved The default is CASHM Folder 3 Data File Folder This is one of the sub directories created during the initial setup Set the path 15 for the filter parameters file that contains the peak detection thresholds and filter parameters Once the input settings are entered users can execute the program by pressing the Create and Save Input File control 16 This will result in the creation of a Inputs file in the main directory C SHM Folder DAQ Inputs If a previously created input file exists in the main directory the program will prompt the users to choose if the existing input file is to be replaced by a new input file Once the input file is created stop the program by pressing the STOP control 17 Figure B 3 Screen shot of 3 Input VI
201. thstand years of exposure to the elements The installation requires less skill than bondable strain gages and can be done in virtually any environment The gages can be attached to a steel member with the use of a low power capacitive discharge spot welder The time required for sensor installation depends on the accessibility but in typical situations would take less than 30 minutes per gage The cost of the Hitec Products weldable strain gage varies depending on the type e g half full bridge etc but typically ranges between 50 100 per gage plus the cost of lead wire approximately 0 25 per foot 2 3 2 Data Acquisition Equipment As mentioned in Section 2 2 the field monitoring software was designed to function with IOtech instrument hardware StrainBook 616 and its expansion module WBK 16 that are shown in Figure 2 25 StrainBook 616 is a portable strain gage measurement system that connects to a PC s Ethernet port Each unit comes with eight built in strain channels The StrainBook 616 contains a 1 MHz A D converter that is capable of scanning all selected channels at 1 micro second and continuously transmitting collected data to a host PC The maximum sample rate per channel is 1 MHz divided by the number of channels selected For example if all 8 channels are configured the maximum sampling rate is 125 kHz The StrainBook 616 is capable of accepting input from strain gages configured for full half or quarter bridge configurat
202. tive l 2 8 8 0 0435 5 5 2 8 4 0 0435 5 5 2 2 8 6 0 0435 5 5 2 8 12 0 0435 5 5 2 2 8 6 0 0435 5 5 2 8 4 0 0435 5 5 2 8 10 0 0435 5 5 5 2 8 8 0 0435 5 5 78 a Sensor 1 c Sensor 3 5 14 Freparcy dt e Sensor 5 1 1 is ft tan ce oe KOS oe f Sensor 7 t PRO b Sensor 2 1 2 3 t 7 1 2 A 2 d Sensor 4 i t i H 4 e 1 5 o n Wo uw 3 9 Y SS f Sensor 6 T oe 07 9 megere Mr h Sensor 8 Figure 3 8 PSD plot from sample data with no traffic on the bridge 79 1 E RO BRR 1 1 1 4 5 t d i 3 1 2 n 1s 1 1 1 n n ie Sensor 1 b Sensor 2 5 J 4 1 a 3 4 gt Ld LI 0 5 3 3 Lu 22 t 4 LI 0 3 n 13 a c Sensor 3 d Sensor 4 OST TTS EET ETT TET SST TTT ha a ee e Sensor 5 f Sensor 6 i x l 4 L z 3 Mopar 3 D g Sensor 7 h Sensor 8 Figure 3 9 PSD plot from sample data with traffic on the bridge 80 yeod pue II uo PIJP Jo
203. tor and a 9 slot screw terminal block The adapter plugs into channel input DB9 connectors on StrainBooks and WBKI6 expansion modules With use of the terminal block and appropriate shorting of jumper pads the user can easily set up the desired bridge configuration A table indicating bridge types and the respective CN 189 jumper pad shorts follows shortly In some cases the user may want to install a resistor at location RI The electrical relation of CN 189 components shown in the following schematic StrainBook 16 User s Manual 92994 Bridge Configurations 613 C 22 se O E RA EX CN 189 DB 9 Adapter Option The CN 189 is intended for convenience and is not shielded Higher signal quality will be obtained with the use of shielded cables such as the CA 177 strain gage cable P4 7 Pad Jumper CN 189 Schematic The CN 189 can be configured to utilize the components of an installed CN 115 oe CN 115 1 in accordance with the following table EW Intemai Exc nion Sense Short and 2 lane ilie Short 3 and 4 ee Me Brig Usi 2 Wire Short 5 ad sl T he iade ah Gain Amp Ground Path Short Short Sand 6 1 Ground Path E5 between 5 and 6 7 High Gain 4 p RE Ground Path INT ca High Gain Amp Ground Path High Gain Ground Path T 1 4
204. ual Setup and Connecting tha Ethernet 5 5 C 6 LAN with no DHCP Server Local Area Network with no Dynamic Host Configuration Protocol server This scenario looks the same as that shown in the previous illustration except there is no Dynamic Host Configuration Protocol DHCP In this type of setup one or more computers are connected to a network and each computer has a static address STEP 3 Connect the System Components Reference Note For examples of StrainBook 616 system connections including cable use refer to Chapter 3 Connectorr and Indicators and Chapter 11 System Expansion Wheat you will need to connect a Strain Book 616 to the Ethernet An available connection to the Ethemet The connection can be either an Ethernet jack on computer or an Ethernet jack on a hub that is connected to the Ethernet AnEthemet patch cable e g CA 242 1 5 foot cable CA 242 7 7 foot cable 1 Connect the Exhernet cable to the Ethernet jack on the StrainBook 616 Connect the other end of the cable to the Ethernet jack on the host computer oc network hub STEP 4 Power up the System Components When powering up StrainBook 616 system It is Important that the StrainBook 616 ls powered 9 last and that the most remote system components are powered first Other power up sequences may result In software s fallure to recognize all components First
205. uired to identify and extract the desired characteristics Storage of a large volume of collected data can also cause problems since it may require significant disc space To address these issues significant attention was 30 given to incorporate data reduction and processing algorithms so that only the useful information is used and retained 2 2 1 4 Results Presentation In addition to efforts related to data processing and storage significant attention was given to ensuring that the system presents useful evaluation results to the user As will be illustrated subsequently the field monitoring software was developed to provide users with following information e Identifying and notifying alarming events e Traffic event history e Statistical trends One of the main purposes of the field monitoring software is to deliver users information that can be used to identify potential damage and gradual changes in bridge performance In order to meet this goal two options were added First an option was included that allows users to receive a notification of any alarm event When this option is selected the program will send a message upon occurrence of an alarm event via email that includes the date and time of each occurred event sensor identification cause of event either overload or impact and the magnitude of the event Furthermore in order to allow users to access and review the archived and or received data files the software was
206. uisition processing and communication system consists of the StrainBook 616 data acquisition instrument a 1 GHz Dell desktop host PC and a wireless router These hardware components were installed in an environmentally controlled aluminum cabinet shown in Figure 3 5 to protect them from weather and vandalism The cabinet was mounted on the north corner of the west abutment wing wall and was supplied with electrical power through direct feed from an existing underground line Note power could also be supplied by solar power The cabinet is equipped with a light bulb a fan and two thermostats to provide temperature control 67 The connection between the sensor wires and the StrainBook 616 and between the StrainBook 616 and the router were made in accordance with the product manual provided in Appendix C The StrainBook 616 data acquisition instrument and the host PC were both connected to the router with Ethernet cables creating a local area network that allows direct communication among the hardware components The network at the bridge site was due to fortunate proximity then connected to Iowa State University ISU network via wireless communication 68 utres oSpr1q p c ueds uonoog 9 ueds puo 180M y uonoes 9 YOSNAS YOSNAS 8 3IOSNHS 5 MOSNAS hs E 7 e 17705546 T 6 WOSNAS TT T
207. ule 4 performs the analysis The last module postprocessor 5 was designed for reviewing the analysis results Figure 2 2 schematically depicts the organization and hierarchy of each window within BEC Analysis Screen shots of each window are presented in Figures 2 3 through 2 11 with the various windows text box controls frames command buttons and other indicators numerically labeled in each figure The features included in each window and the general procedures for running BEC Analysis are discussed in the subsequent sections In addition descriptions of each of the controls indicators and command buttons and the principle procedures required to run BEC Analysis are provided in Appendix A 2 1 2 1 Bridge Information Window BEC Analysis can be started by double clicking the program icon Once the program has loaded the BEC Analysis title screen shown in Figure 2 3 will appear By clicking the Click to START command button on the title screen the program will be initialized and move to the next window that contains the General Information frame shown in Figure 2 4 In this frame the number of spans 2 and boundary conditions 3 can be specified The number entered in the Number of Spans text box control 2 will dictate how many Span Description windows 5 in which information for each span will be entered will be needed The Boundary Condition 3 frame contains controls which allow the user to specify th
208. uonimsinboy Axeunugasd aeach wy ag Keuuiasg 23 pued uo A sis4qpuy 154 114 30 JOYS UNS ST Z AMIA 108095 10 1018 164 144 9 TE 5 E BNIH33NIGN3 5 WLS 8 4105025 94osuas G osuas p osuas ae 105095 THOUS p 001 AN 2 01 9002 Aeuruya d 12P O4 WHS 36 lt 1 JOSUAS 10 weng q Arms uen 1649 054 1337 Kl 37 lt 1 ans Ke ds p 1o3 14 38 pued A 7ndug JO JOYS 91 7 IMZA pue Jis opos Wess BN PT CPO WIAD ee OD Pe 7721 OPP WEIS TT TTT TT NL Ro CD GD OD GU CD Gi ETE 4 9 jauuey 5 uuu auuey2 jauueyD Z auueu 39 pued yuo JA c7 90 V quip jo 5305 1T C VANS qe uonismboy ejeq uey Jo uonexsnj e SUNOS 131837 ovi ONE 781 8 1038 DN i f LLISHJAINN 11 16 oc
209. used to generate thresholds which are used for identifying isolated events The field component includes hardware and field monitoring software which performs data processing and evaluation The hardware system consists of sensors data acquisition equipment and a communication system backbone The field monitoring software has been developed such that once started it will operate autonomously with minimal user interaction In general the SHM system features two key uses First the system can be integrated into an active bridge management system that tracks usage and structural changes Second the system helps owners to identify damage and deterioration 17 Key Words 18 Distribution Statement analysis bridge evaluation overload structural health monitoring No restrictions 19 Security Classification of this 20 Security Classification of this 21 No of Pages 22 Price report page Unclassified Unclassified 219 NA Form DOT F 1700 7 8 72 Reproduction of completed page authorized EVALUATION OF STEEL BRIDGES VOLUME II STRUCTURAL HEALTH MONITORING SYSTEM FOR SECONDARY ROAD BRIDGES Final Report December 2007 Principal Investigator Brent M Phares Associate Director Bridge Engineering Center Center for Transportation Research and Education Iowa State University Co Principal Investigators Terry J Wipf Director Bridge Engineering Center Center for Transportation Research and Education Iowa State University
210. ve Parameters for When pressed filter parameters and event detection Selected Sensor Control threshold specified in control 12 for a selected sensor will be stored 20 19 Create File for Filter Contains controls and indicators used for writing and Parameters Tab Control saving filter parameters and event detection thresholds for each sensor in a text file 20 Parameters Table Temporarily stores the filter parameters and event Indicator detection thresholds for each sensor specified in control 12 21 Filter File Save Path Path to which a text file that contains filter parameters Control and event detection thresholds for each sensor will be saved 22 Create File for Filter When pressed a file containing filter parameters and Parameters Control event detection thresholds for each sensor will be saved to the path specified in 20 23 STOP Control When pressed the program will stop B 18 Table B 3 Description of selected controls and indicators in 3 Input VI Control or Indicator Description 1 StrainBook 616 Channel Channels of StrainBook 616 to be activated When Control selected Ctrl mouse click the indicator turns blue 2 WBK16 Channel Channels of WBK16 expansion module to be activated Control When selected Ctrl mouse click the indicator turns blue 3 Sensor Configuration Parameters that need to be configured for each sensor Controls 4 Device Name Control
211. which follows a licensing agreement select Strain Book 616 from the drop down list and follow the on screen instructions Reference Notes Adobe Acrobat PDF versions of documents pertaining to StrainBook 616 are automatically installed onto y our PC s hard drive as part of product support at the time of software installation The default location is the Programs group which can be accessed via the Windows Desktop Start Meme Setup and Connecting to the Ethernet 006616 User s Manual C 3 C 1 3 Ethernet Connection and System Power up Ethernet Connection and System Power up Ethernet connectivity can only be used with Windows NT Windows 2000 or Windows XP operating systems Overview Strain Book 616 Rear Panel StrainBook 616 connects directly to Ethernet port on PC or network hib via the unit s built in lo T00BaseT Ethernet interface An Ethemet patch cable CA 242 1 5 foot or CA 242 7 7 foot cable is ued to make the connection Note that either straight through or cross over cable may be used The circuitry automatically adjusts for the cable type to ensure proper connection Connecting a StrainBook 616 to the Ethernet Turn off power to the system devices and externally connected equipment before connecting cables Electric shock or damage to equipment can result even under low voltage conditions Take ESD precautions packaging proper handling grounded wrist strap etc
212. wing IP Address radio button 7 Set the IP address field to 10 0 0 x where x is some number from 1 to 254 Make sure that euch computer on the dedicated network has a unique IP address 8 Set the Subnet mask to 253 0 0 0 Note that the remaining fields can be left unchanged SureinBock 6 16 User s Manual min Setup and Connecting to the Ethernet 5 9 C 10 STEP 6 Configure Device Network Settings using DaglPConfig Applies only to a LAN Local Area Network which has a no DHCP server If using a LAN Local Area Network which has DHCP server skip this section and continue with STEP Configure and Test the System using DagConfiguration Applet page 5 11 Ensure that the serfal number displayed for the unit being configured agrees with the serial Multiple devices on LAN are each identified by their unique device specific serial number number on the MAC label located on the rear panel of the device The Dag PConfig applet allows you to change the IP address of a device to match the address of a host computer The applet is located in the program group for the associated device and can be accessed from the Windows Desktop via the start menu Reference Note Appendix A contains general information regarding how to use the Dag Configuration Applet 1 Locate the DaqiPConfig Applet Locate the DaqIPConfig applet by navigating from the Windows Desktop as follows Select a device lo vies r change 4s nehaok
213. wo readings are acquired from a bridge The first reading is obtained with the bridge in its quiescent state the second is taken with one leg of the bridge shunted by one of three selectable resistors The resistors are located on plug in header inside the StrainBook WBKL6 module Shunt calibration appears as Shunt RE Shunt and Shunt in the list of calibration methods The Internal Shunt Calibration requires that the user enter the following 7 parameters Excitation The value of the constant voltage source used 1o excite the gage Gage Factor The Gage Factor value of the gage used in the bridge A Gage Factor of 2 is typical Shunt Ohms The value in Ohms of the shunt resistor mounted on the header inside the StrainBook or WEKL6 module Bridge Ohms The resistance value of the gage Typically 120 or 350 Ohms Max Load The maximum load value the gage is expected to measure This value could be less than the max rated load of the gage Quiescent Load The at rest value of the load applied to the gage If no load will be applied to the gage in its quiescent state enter 0 zero Point 1 Units The minimum load value the gage is expected to measure This value could be greater than the minimum rated load of the gage Example Excitation voltage ts set to 2 volts A Quarter Bridge circuit employing a 350 Ohm strain gage with a Gage Factor of 2 and a full load rating of 1500 pe is connected to Strain
214. y 25 300 017 27 07 7 07 7 7 M 7 200 dd 47 47 47 17 17 7 7 7 7 7 7 7 7 7 7 72727 1004 IRD DDD 20 07 27 27 LTT T4 RIT TET T 0 30 60 90 120 150 180 V Midnight Microstrain a Hourly event histogram for Nov 16 Thursday 2006 800 1 700 4 600 1 gt 27 27 TIT ITT TTT TTT TTT 2 4004 7 07 07 07 07 07 17 07 0707 29 70 7 7 49 47 7 7 07 7 47 07 07 47 47 47 47 07 47 7 47 07 7 7 300 4 27 07 27 7 7 07 27 ggg agg 200 7 7 07 07 7 22 2 07 7 2 7 17 17 00 7 7 4 ap rp Lp ap ep 7 7 47 47 7 7 07 47 47 7 07 47 47 47 47 07 47 47 47 7 T 47 7 47 7 gt gt gt 07 7 2 gt 7 gt 2 100 um ap 7 7 7 7 L7 7 A7 47 07 07 17 T 7 T 7 47 7 7 47 07 47 7 47 7 7 7 7 7 PF 7 7 7 7 7 7 47 7 7 7 47 27 27 7 7 47 47 47 47 47 47 7 7 7
215. y distributed load whose magnitude is specified in 43 will be applied only to checked spans s This frame will be enabled when the Truck Train option 41 is selected 746 Iowa Legal Loads HS 20 Frame Lists types of Iowa legal trucks and HS 20 trucks This frame will be enabled only when the Iowa Legal Loads HS 20 option 40 is selected Upon selection information on axle configuration and weight of each axle wheel line load for a selected load will be automatically assigned to 49 and 50 47 Distribution Factor Control Distribution factor that will be used in the analysis 48 Impact Allowance Control Dynamic load allowance or impact allowance that will be used in the analysis 49 Axle Load Control Weight of each axle wheel line load to be entered manually or assigned by 46 Number of controls that will appear on the screen will be dictated by 44 50 Distance Between Axles Control Distance between each axle to be entered manually or assigned by 46 Number of controls that will appear on the screen will be dictated by 44 51 Axle Configuration Display General graphic representation of defined axle configuration on a model bridge Axle configuration display will change according to the options 44 or 46 selected 52 Analysis Window Allows users to run analysis and view absolute maximum results either at a designated location or in each span 53 In Each Span Option Option fo

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