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Presel - DNV GL

1. Presel SESAM 5 60 01 OCT 2004 Program version 7 3 PRINT supno ALL supno CPU TIME ESTIMATES IN REDUCTION rear ELEMENT LOAD NODE id OVERVIEW OF SUPER ELEMENTS STATUS SUPER ELEMENT HIERARCHY supno index trano TRANSFORMATION ALL END END PURPOSE The command prints data in tables on screen and to file The destination depends on what to print e g PRINT ALL goes to file whereas PRINT STATUS goes to the screen The SET PRINT DESTINATION command overrules these default destinations Long prints are broken into several sub tables each limited to a certain number of lines When printing to screen in interactive mode enter CONTINUE to print the next sub table or END to stop The SET PRINT PAGESIZE command changes the number of lines contained in each sub table PARAMETERS supno ALL CPU TIME ESTIMATES IN REDUCTION ELEMENT LOAD Print to file all data for the superelement supno Print to file all data for all superelements Print on screen CPU time estimates for the reduc tion Select a single or all superelements See ex ample print in Section 3 8 Print on screen information on superelements in cluded in the current superelement See example print in Section 3 8 Print on screen information on loads The com mand is described in detail in the following SESAM Presel Program version 7 3 NODE OVERVIEW OF SUPER ELEMENTS STATUS SUPER ELEMENT HIERARCHY TRANSFORMATIO
2. E Define thickness PROPERTY THICKNESS ALL SURFACES INCLUDED 0 05 Define and connect material PROPERTY MATERIAL CONCR ELASTIC 0 3E11 0 25 2500 0 0 CONNECT MATI ERIAL CONCR ALL SURFACES INCLUDED END Define loads PROPERTY LOAD 1 GRAVITY GLOBAL FLEXIBLE PART CONTRIBUTION 0 0 9 81 END LOAD 2 NORMAL PRESSURE ALL SURFACES INCLUDED 1500 END MIDDLE SURFACE END Create mesh MESH ALL The model is now complete Exit Prefem A2 3 Superelement 3 Prefem input for creating superelement number 3 the short wall od Ne AP AP First create geometry GENERATE SURFACE A 1 2 1 2 1 2 1 2 END CARTESIAN 0 0 0 8 0 4 0 END O 0 3 END Then select 8 node shell element to be used SET ELEMENT TYPE SURFACE ALL SURFACES INCLUDED SHELL 8NODES T T foe l l l Define supernodes PROPERTY BOUNDARY CONDITION ALL LINES INCLUDED SUPERNODE SUPERNODE SUPERNODE SUPERNOD GLOBAL CJ CI SUPERNODE SUPERNOD Define thickness PROPERTY THICKNESS ALL SURFACES INCLUDED 0 04 Define and connect material PROPERTY MATERIAL CONCR ELASTIC 0 3E11 0 25 2500 0 0 CONNECT MATI Gl RIAL CONCR ALL SURFACES INCLUD 7
3. D END Presel APPENDIX A 6 01 OCT 2004 Define loads PROPERTY LOAD 1 GRAVITY GLOBAL FLEXIBLE PART CONTRIBUTION O END LOAD 2 NORMAL PRESSURE ALL SURFACES INCLUDED 1500 END Create mesh MESH ALL The model is now complete Exit Prefem Ao SESAM Program version 7 3 0 9 81 END MIDDLE SURFACI Gl oP Je A 2 4 Superelement 4 Prefem input for creating superelement number 4 the floor JP AP AP AP AP First create geometry GENERATE SURFACE A 1 2 1 4 1 2 1 2 END CARTESIAN 0 0 0 7 0 0 END O 4 0 END Then select 8 node shell element to be used SET ELEMENT TYPE SURFACE ALL SURFACES INCLUDED SHELL 8NODES T o l l l Define supernodes PROPERTY BOUNDARY CONDITION ALL LINES INCLUDED SUPERNODI CJ SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE GLOBAL Define thickness PROPERTY THICKNESS ALL SURFACES INCLUDED 0 05 Define and connect material PROPERTY MATERIAL CONCR ELASTIC 0 3E11 0 25 2500 0 O CONNECT MATERIAL CONCR ALL SURFACES INCLUDED END Define loads PROPERTY LOAD 1 GRAVITY GLOBAL FLEXIBLE PART CONTRIBUTION 0 END LOAD 2 NORMAL PRESSURE ALL SURFACES INCLUDED 3000 END E Create mesh MESH AL
4. Nodes of the Asterisk here Nodes of the Summary Coordinates in the superelement signals discrepancy of superelement information cartesian system of the being included boundary conditions assembly superelement assembly Figure 5 3 CHECK INCLUDE tabulates match between nodes here for first level superelements The table header contains information about including a superelement in the second level superelement assembly 21 The coordinate tolerance is 0 1 see the SET COORDINATE TOLERANCE command The table contains the following information e The first line marked A says that the node 11 1 101 a triplet of the superelement being included matches node 11 2 103 a triplet of the superelement assembly And the coordinates of these nodes are 20 20 0 The fourth line marked B says that node 11 1 303 of the superelement being included does not match any node of the assembly Its coordinates are 2 18 20 The summary at the bottom says that the assembly has 1 node not matched by any node of the superelement being included 3 pairs of nodes match 3 nodes of the superelement being included does not match any of the assembly nodes and the total number of nodes in the assembly counting the ones of the superelement being included is 7 SESAM Presel Program version 7 3 01 OCT 2004 5 27 Higher level superelements will have nodes with more than one triplet see Section 3 2 6 When higher level superelements are
5. Figure 4 1 The file environment of Presel The files are e The command log journal file JNL is an ASCII file on which all commands and data given to the program are logged This means that both data typed or clicked by the user and data read by the pro gram from a command input file will be logged However commands not changing the model and data base e g a command displaying data will not be logged The time of opening and closing the model file is also logged The file is very useful as a backup file both for verification purposes and for later use as a command input file The command log file can be read and modified by a text editor The command input file JNL is an ASCII file which may be read into the program The commands contained on this file will have the same effect as if they where given by the user directly The file is processed by using the command SET COMMAND INPUT FILE followed by ALL the latter command means read all commands found on the file Alternatively you may specify a com mand input file when starting Presel from Manager The model file MOD is the binary data base containing all model data The file cannot be read by a text editor The print file LIS is an ASCII file which contains tables over data requested for printing by the PRINT command Presel SESAM 4 4 01 OCT 2004 Program version 7 3 The plot fi
6. END PURPOSE The command defines loads for the current superelement by combining loads of the included superelements The current superelement must be a second or higher level superelement The loads may be combined one by one explicitly or a group of loads may be combined See Section 3 3 for an explanation of the princi ples of combining loads Several superelement occurrences superelement number and index and several local load cases belong ing to the superelement occurrences may contribute to a single global load case of the current superele ment The local load cases llc of included first level superelements need not exist prior to giving this command warnings are then given saying that the input is accepted even though the local load cases are unknown Prior to running the analysis however the local load cases must have been created Read the note in Section 3 3 4 on this The load combinations may be verified by the PRINT LOAD command PARAMETERS glc A single global load case number to be defined for the current superelement supno index Superelement number and index of an included superelement llc Local load case number of the included superelement contributing to glc factor Factor to apply to the local load case GROUP A group of global load cases is to be defined lowglc higlc step The lowest and highest global load case numbers and the step increment in numbering An example
7. Linear dependencies in a transformed coordinate system may be specified by first assigning a transforma tion to the dependent and independent nodes using the BOUNDARY command 3 7 Sets The command TAG may be used to define a set of nodes that may be referred to by the option TAGGED in for example the BOUNDARY command see Section 3 5 In effect this is therefore a set of nodes with the pre defined name TAGGED When you create a new higher level superelement by the ASSEMBLY NEW command the set TAGGED is empty until you put nodes into it The set will not be changed by moving between the superelements by the ASSEMBLY OLD command or by exiting and re entering Presel You may refer to the complementary set of nodes by the pre defined name UNTAGGED The command UNTAG is used to remove nodes from the set TAGGED In addition to the set TAGGED you may define any number of named sets of nodes by the DEFINE SET command The standard set operators UNION WITH SUBTRACT BY and INTERSECTION WITH are used to define the sets A set that contains supernodes will be available also within an assembly into which the superelement is included This is provided that the set was defined prior to including the superelement A set containing supernodes defined for a first level superelement in Prefem and Preframe will also be available in assem blies Note that if a set contains both supernodes and other free or fixed nodes then the set at assembly level will
8. DNY SESAM USER MANUAL Presel Preprocessor for Assembling Superelements DET NORSKE VERITAS SESAM User Manual Presel Preprocessor for Assembling Superelements October 1st 2004 Valid from program version 7 3 Developed and marketed by DET NORSKE VERITAS DNV Software Report No 82 6113 Revision 8 October 1st 2004 Copyright O 2004 Det Norske Veritas All rights reserved No part of this book may be reproduced in any form or by any means without permission in writing from the publisher Published by Det Norske Veritas Veritasveien 1 N 1322 Hovik Norway Telephone 47 67 57 99 00 Facsimile 47 67 57 72 72 E mail sales software sesam dnv com E mail support software support dnv com Website www dnvsoftware com If any person suffers loss or damage which is proved to have been caused by any negligent act or omission of Det Norske Veritas then Det Norske Veritas shall pay compensation to such person for his proved direct loss or damage However the compensation shall not exceed an amount equal to ten times the fee charged for the service in question provided that the maximum compensation shall never exceed USD 2 millions In this provision Det Norske Veritas shall mean the Foundation Det Norske Veritas as well as all its subsidiaries directors officers employees agents and any other acting on behalf of Det Norske Veritas 1 1 1 2 1 3 1 4 2 1 2 2 2 3 3 1 3 2
9. Presel SESAM 3 10 01 OCT 2004 Program version 7 3 3 2 3 Auxiliary Commands You may verify the superelement assembly by various auxiliary commands The LABEL COUPLED NODES command used in Figure 3 4 and Figure 3 5 verifies that the appropriate number of first level superelements are indeed coupled This is an important check because a minor coordi nate difference for example due to a modelling error may involve that some nodes are not coupled even though they appear to be so in the display A coordinate tolerance determines whether nodes are coupled or not You can set this tolerance by the SET COORDINATE TOLERANCE command The LABEL NON COUPLED NODES is the complementary command labelling nodes adjoined by a single first level superelement by the digit 1 The node in the lower right corner of superelement 7 is such a node The command PRINT OVERVIEW OF SUPER ELEMENTS produces a table over all first and higher level superelements A double plus in the left margin of the table indicates which superelement is the cur rent one The DISPLAY command displays the current superelement the INCLUDE command includes superelements into the current superelement etc For the example above the table looks like this SUPER EL TYPE LEVEL NODES ELEMENTS LOADCASES 5 al 16 9 3 6 1 10 4 2 7 2 10 3 0 The command PRINT SUPER ELEMENT HIERARCHY produces a table illustrating the hierarchy For the current example th
10. SPRING TO GROUND and DAMPER TO GROUND ORIGIN SYMBOLS The symbol for the origin will be re sized to the given value size Symbol size in mm Presel SESAM 5 74 01 OCT 2004 Program version 7 3 SET PLOT ON COLOUR Onn FILE prefix filnam number CGM BINARY HPGL 2 FORMAT HPGL 7550 POSTSCRIPT PLOT SESAM NEUTRAL WINDOWS PRINTER ORIENTATION PORTRAIT Al A2 PAGE SIZE A3 A4 AS PURPOSE The command sets parameters for plotting The settings must be done prior to giving the PLOT command PARAMETERS COLOUR Switch ON or OFF colours The default is OFF Colours are supported by the for mats PostScript HPGL 2 and CGM Give this command after the SET PLOT FILE FORMAT commands and prior to the PLOT command FILE Set the name of the plot file By default it is the same as the model and command log files The extension of the plot file depends on the plot format see the SET PLOT FORMAT command Note that the command closes the current plot file if such exists enabling this to be sent to a laser printer without having to exit Presel prefix Prefix of the plot file filnam Name of the plot file FORMAT Set the plot format SESAM Program version 7 3 number CGM BINARY HPGL 2 HPGL 7550 POSTSCRIPT SESAM NEUTRAL WINDOWS PRINTER ORIENTATION PORTRAIT PAGE SIZE Al A2 A3 A4 A5 NOTES Presel 01 OCT 2004 5 75 The plotter number may alternatively be gi
11. VOLUME a box in space defined by two diagonally opposite points The planes are parallel with the coordinate system planes Figure 5 1 Node select alternatives 2nd pnt PARAMETERS GLOBAL COORDINATES The lines planes and volumes subsequently given are to be in terpreted in the cartesian coordinate space of the superelement in question USE COORDINATE SYSTEM The lines planes and volumes subsequently given are to be in terpreted in the subsequently named cylindrical coordinate space coord name Name of a previously defined cylindrical coordinate system SESAM Program version 7 3 O supno index nodeno SINGLE GROUP nodel node2 nstep LINE SEGMENT INFINITE NODE COORDINATE xyz LOCAL COORDINATE r phi z PLANE 3 PLANE 2 PLANE Presel 01 OCT 2004 5 5 Parentheses enclose one or several node number triplets First level superelement number to which the node belongs First level superelement index to which the node belongs Node number A single node is to be selected A group of nodes are to be selected The first node number The last node number The step increment in node numbering between nodel and node2 All nodes on a straight line or straight in a specified cylindri cal coordinate system defined by two points are selected The tolerance or thickness of the line is defined by the SET CO ORDINATE TOLERANCE command Only the nodes on the line be
12. Add node numbers A choice must be made between various al ternatives To understand these alternatives see Section 3 2 6 about node numbers Add only the node number of a given first level superelement Superelement number and index of a first level superelement Add only the internal number of the current superelement as sembly normally this is of little interest to the user Add one or all node number triplets the full and unique ref erences to nodes see Section 3 2 5 about triplets SESAM Program version 7 3 supno index ONE NODE NUMBER TRIPLET ALL NODE NUMBER TRIPLETS NODE SYMBOLS ALL NODES SUPER NODES ONLY NON COUPLED NODES ORIGIN SYMBOL node symbols boundary condition symbols yy SO PG VO Figure 5 9 Presel 01 OCT 2004 5 45 Select one of the possibly several triplets by giving superele ment number and index Only one of the possibly several triplets is shown The program automatically selects which of the triplets to show All triplets are shown reflecting the fact that the nodes have one triplet for each first level superelement connected Add node symbols All node symbols are shown Only supernode symbols are shown Add the number 1 to the display for all nodes to which only a single first level superelement is coupled There will be no label for nodes where two or more first level superelements are cou pled This alternative is the complement to COUPLED NODES Add a
13. Define supernodes on two lines PROPERTY BOUNDARY CONDITION AI12 AJ21 SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODI GLOBAL E Define thickness PROPERTY THICKNESS ALL SURFACES INCLUDED 01 Define and connect material PROPERTY MATERIAL STEEL ELASTIC CONNECT MATERIAL STEEL ALL SURFACES INCLUDED END Define line load PROPERTY LOAD 8 LINE LOAD AJ11 GLOBAL 1 5 0 0 7 T Create mesh MESH ALL The model is now complete Exit Prefem O Je A 1 2 Superelement 6 Prefem input for creating superelement number 6 Semicolons are used to accept default values HP AP AP AP AP AP oP First create geometry GENERATE SURFACE A 1 2 1 4 1 2 1 1 END CARTESIAN 0 0 0 4 00 END 0 1 0 END Then select 4 node shell element to be used SET ELEMENT TYPE SURFACE ALL SURFACES INCLUDED SHELL 4NODES 7 Define supernodes on two lines PROPERTY BOUNDARY CONDITION AI11 AJ21 SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODI GLOBAL EJ SESAM Presel Program version 7 3 01 OCT 2004 APPENDIX A 3 Define thickness PROPERTY THICKNESS ALL SURFACES INCLUDED 01 Define and connect material PROPERTY MATERIA
14. SESAM Presel Program version 7 3 01 OCT 2004 5 43 INCLUDE supno TRANSLATE TRANSLATE dx dy dz PURPOSE The sub command translates the superelement being included along the axes of the superelement assembly PARAMETERS dx dy dz The translations in X Y and Z Presel SESAM A OCA Programversion 7 3 LABEL BOUNDARY CONDITION SYMBOLS COUPLED NODES EXTERNAL NODE NUMBER supno index INTERNAL NODE NUMBER NODE NUMBERS supno index LABEL NODE NUMBER TRIPLET ONE NODE NUMBER TRIPLET ALL NODE NUMBER TRIPLETS ALL NODES NODE SYMBOLS SUPER NODES ONLY NON COUPLED NODES ORIGIN SYMBOL PURPOSE The command adds labels boundary condition symbols node numbers etc to the display The labels are shown until a new display is made the label command may then be re entered The size of the symbols are adjusted by the SET GRAPHICS SIZE SYMBOLS command The symbols used are shown in Figure 5 9 PARAMETERS BOUNDARY CONDITION SYMBOLS COUPLED NODES NODE NUMBERS EXTERNAL NODE NUMBER supno index INTERNAL NODE NUMBER NODE NUMBER TRIPLET Add symbols showing fixations of d o f s Add numbers to the display telling how many first level su perelements there are coupled to each node The numbers are only given for nodes where two or more first level superele ments are coupled i e the number will always be 2 Also see the NON COUPLED NODES alternative
15. choose either X Y or Z Translations in X Y or Z directions R X R Y or R Z Rotations about the X Y or Z directions beta New linear dependency factor SESAM Presel Program version 7 3 01 OCT 2004 5 13 CHANGE LOAD NODE lc LOAD END PURPOSE The command changes nodal loads previously defined by the LOAD NODE command Changing a nodal load is done in the same way as it was defined with one exception a load index has to be given The load index is used to distinguish between different nodal loads for the same node for the same load case For example a nodal force defined for the second time for the same node for the same load case is given index 2 The PRINT LOAD command gives an overview of the loads including the automatically assigned load indexes refer to this table when a nodal load is to be changed Rather than describing the CHANGE LOAD NODE command in detail reference is made to the LOAD NODE command Load combinations cannot be changed rather they must be deleted DELETE LOAD COMBINATION and redefined Presel SESAM 5 14 01 OCT 2004 Program version 7 3 COORDINATE SYSTEM COORDINATE SYSTEM coord name CYLINDRICAL COORDINATE x y Z 5 NODE supno index nodeno PURPOSE The command defines a cylindrical coordinate system This coordinate system may conveniently be used for selecting nodes see Section 5 1 and for defining boundar
16. it will have an exact location in that higher level superelement If the higher level superelement is the top level superelement the complete model then the superelement occurrence also represents an actual part of the real structure It follows that only when the complete model is assembled the superelement occurrences may be given their final identifications However rather than assembling the whole model including the top level superelement before introducing the identifications a dynamic way of giving identifications is available By dynamic is meant that preliminary identifications are introduced and thereafter modified during the assembly process until the final identifications are determined when the complete model the top level superelement is created The identification of a superelement occurrence is composed of a name and a location string as follows name location The name is given to a superelement when it is created and is not changed during the assembly process The location string is given when a superelement is included in a superelement assembly The superelement has then become a superelement occurrence in that specific assembly The ocation string is modified during the assembly process 3 4 2 Tutorial in Assigning Unique Identifications for Superelement Occurrences This tutorial takes you step by step through the procedure and commands for assigning unique identifica tions of superelement occurrence
17. ooooonccincninccnonoconcnononononnnonnnoonocono ran croncconnnns 3 12 3 20 sMore About Nodes A Seas aekt Aeevt oases 3 12 Combine AGS 5 Frye A eae cts eee eeu neta eh whe No a Eta 3 13 33 Why Combine Loads niire iminent eron or aan a A o EAE aiii 3 13 3 3 2 Tutorial in Combining Loads One by One c eee ccceesseeteceneceeeeeeeeesecaaeceaeseeeeseeeeeeseees 3 13 3 3 3 Effect on Loads of Rotating and Mirroring Superelements oooooonnoninnnnococoncoonconnnoncconnnos 3 16 3 3 4 Combining Wave Loads by the Group Method ccccccceeseceteeeeeeseeseceeeeeeeeeeeeeeseens 3 17 3 3 5 Load Combinations when Higher Level Superelements are Repeated oooooonncnncnn cc 3 20 3 3 6 Requirement to Assembling Process when Wave Loads are Computed cece 3 21 Assemble LO tii ii id rin 3 23 3 4 1 Principles of Uniquely Identifying Superelement Occurrences ccocoioonnocononcnononannonncnnnoos 3 24 3 5 3 6 3 7 3 8 3 9 3 10 4 1 4 2 4 3 5 1 5 2 3 4 2 Tutorial in Assigning Unique Identifications for Superelement Occurrences 3 24 3 4 3 Tutorial in Using the LOAD ASSEMBLY Command c cc cceecceesessceteeesseeseceseeeneeenes 3 31 3 4 4 Advice on Giving Unique Identifications to Superelement Occurrences mcoiccionninnnn 3 33 Boundary Conditions ido feats eon 3 35 Linear Dependency vi2 2iica ceseva Borsa etead tose id 3 36 SE E E satutel Sedat laren a dde dace taalgestcts 3 37 Display and Pri tt
18. 3 38 Practical and Efficient Application of the Superelement Technique ooooonnoccnocononononononononoonnc nnonos 3 41 Node Numbering Optimization to Minimise the Bandwidth oooocnncnnncninonionnonnconocononononancnncc nncnos 3 43 EXECUTION OE PPRESEL 00 ssscesesdeii soxeuscdnitete nine svveasensavesnecdaetaphevaradetusdetensarenassestuadsousee 4 1 Program Environment ccccccccessessseesceeseceseceeeeeeeessecscecsaessecseeceseecsaecseceseseaeseseesaecsaeceseseeeensecseseaeens 4 1 4 1 1 Starting Presel from Managet ccccccccccsccssecsseeseceeeceseecseeeseceseceeeeeseeeseenaeceseceeeeeeeenseenaees 4 1 4 1 2 Line Mode Input of Commands and Arguments ccccccccsecesceeeceeseeseeneceseeeseeeeeeeseensens 4 1 4 1 3 Filessused by Presea asias 4 3 4 1 4 Creating Plots for Reports ccccccccsccesseessessecseceeceeecescecseecsecesecseseaeeeseesaeceseseeeeneeeaeenaees 4 4 4 1 5 Command Line Argument noiera e 4 4 Program Requirements cccccsccsccssscesseessecsseeseceeceseceseeesecseceseseeeseneesaecsaeceeseeeeeecaeecaeenseenaeeseceaeens 4 6 ADA Execution Md da on 4 6 AD 2 SOALE SPACE ra iras 4 6 Program Limitations a A n 4 6 COMMAND DESCRIPTION iesscscssssssessssessactosncsesoasssessssesesssucssosecasanscacceasssedadesusscdenacsess 5 1 Node Select Features A A A A ade Ml ata 5 2 Silly Line mode Selection ii a a ea ee a iia 5 2 51 2 Graphical Selec cid erea E EEE A E E veel AE VEE 5 2 5 1 3 Command Syntax for
19. 81 WRITE A A IT A AR Ad alii 5 82 LOMA A A E 5 83 A A A A A E tea ela sen eed ec date 5 84 APPENDIX A TUTORIAL EXAMPLES sisssccvsssovcssssoossosssesvencsevesssssecdssesiseerscstidonsennsseguansdedasioe 1 A 1 The Tutorials in Assembling Superelements and Combining Loads oooconiccnoconocnnonnnocnnnnconnconoconos A 1 ATT lt Super lement S nioran ees aerea e E dE lek EA A 1 AZ Superelement O it A AA A Add dias A 2 A2 The Tutorial in Assembling Loads cccceccccssessseseceseceeceeeeeeeecsaecsseeseceeeeseecsecseceseseeeesaeeaaeeaeess A 3 AZI Superelement Tinianin na ra aa a iaa a AA a a aR aaa A 4 AA A E A 4 A23 Superelement ri A id ld ii aaa A 5 ADA superelement 4s 25 3548 ese O O A 6 AL SupereleMent tit a tl aaa das A 6 APPENDIX B THEORY sii iaa 1 B1 Mathematical Foundation for Superelement Technique ccccceeccesseessesteceeceeceeeeeeecteeeeeneeenes B 1 Bells Direct Analysis ei AAA de B 1 B1 2 Superelement Analysis cccccccesccescssseeeseescecsseeeeceeeceseeeseecseceseceseseeeeeseeaecseceeeseaeeneeesaes B 2 B1 3 Rotating and Mirroring a Superelement ccc ccceccseesecesecesceesecseeeeeeeeceeeeeseeeaeeeeseenaes B 4 SESAM Presel Program version 7 3 01 OCT 2004 1 1 1 INTRODUCTION 1 1 Presel Preprocessor for Assembling Superelements To use Presel you should know some terms These are highlighted by italic text first time they appear Presel is SESAM s preprocessor for assembling s
20. GLOBAL 0 0 2500 END MIDDLE SURFACE END Create mesh MESH ALL The model is now complete Exit Prefem oe Ae Presel SESAM APPENDIX A 8 01 OCT 2004 Program version 7 3 SESAM Presel Program version 7 3 01 OCT 2004 APPENDIX B 1 APPENDIX B THEORY B1 Mathematical Foundation for Superelement Technique The superelement technique is based on the principle of static condensation reduction of the equation sys tem of part models superelements This involves eliminating the internal free nodes or d o f s from the equation system thereby achieving a reduced equation system containing only the supernodes or super d o f s of the part model The mathematical foundation for the superelement technique is explained in the following by comparing it with a direct analysis i e not using the superelement technique The superele ment technique is only applicable for linear static analysis B1 1 Direct Analysis Figure B 1 Direct Analysis a Single Superelement Figure B 1 shows a very simple plate model The equation of equilibrium for the single superelement which constitute the whole model is Kr R B 1 where K is the stiffness matrix r is the displacement d o f vector and R is the load vector Solving this equation system in one operation yields the displacements for the whole model r K R B 2 Presel SESAM APPENDIX B 2 01 OCT 2004 Program version 7 3 B1 2 Superele
21. HIERARCHY width Decide number of lines printed for each page on file Decide number of lines printed for each page on screen After each page give CONTINUE to print the next page and END to quit printing Note that the default command at this stage is CONTINUE Therefore giving the command semicolon which accepts all subsequent defaults will print all pages Number of lines printed for each page Control appearance of selected tables Switch between TEXT which is default and DIGITS repre sentation of the boundary condition codes See the PRINT NODE BOUNDARY command Set the number of character positions used for each level in the table showing the superelement hierarchy which is printed by the PRINT SUPER ELEMENT HIERARCHY command See the example print in Figure 3 3 Number of character positions The default value is 16 For a superelement hierarchy with many levels e g 6 or more a smaller value may allow the table to be produced correctly A value less than 8 will normally not be meaningful Presel SESAM 5 78 01 OCT 2004 Program version 7 3 TAG TAG select nodes PURPOSE The command tags in effect puts into a set some or all nodes for the purpose of referring to these nodes the TAGGED or to all other nodes the UNTAGGED in subsequent commands e g for defining bound ary conditions Initially no nodes are tagged Tagged nodes are untagged by the UNTAG comm
22. Node Selection ccccccccsssesscessceneeeseeeseceeceneeeseeaeceseceeeseeeenseeasees 5 3 Detailed Description of Commands ccccccecsecsseessesseceseeeneeeseeesceseceaeceseceneeeaeeauecaaeceseeeeeeaeessaeeneens 5 6 ASSEMBLEN aia ai IA a A AAA il 5 8 BOUN ART a ii 5 9 CHANGE td ARA A n 5 11 CHANGE LINEAR DEPENDENGY penisen ia 5 12 CHANGE LOAD cane tie bet AEE AEE ES E S 5 13 EONIRDINA TE STE Maa 5 14 IDE IN ESS ED pect shred so id ds 5 16 DELETE dass os ree ets let an ate 5 17 DELETE LOAD NOD es di 5 19 DISPLA Nr Pa Sees E omnia pie Nin 5 21 E O 5 23 INCLUDE a a A AAA wee 5 25 INCLUDE supno CHECK INCLUDE ccccecceccssssssecesesseeseeeeceeceaeencacseceeeeaeeacesseneenaeenecaaeesenaees 5 26 INCLUDE supno DECODE T MATRITX oo eeccceccccecceceseceeneceescesseaeceeeeceeceeceeecseeeeaaecnaaecneneeneneeesas 5 29 INCLUDE supno DISPLAY meniren e E a a e a a a incida dietas 5 30 INCLUDE supno DISTANCE CHECK 0 cccccceccccesseceeeceeecessaesesaeceececseneeceeeesaeseaaecnsaeeneaeeneneeesas 5 31 INCLUDE supno END DO NOT INCEUDE ccoooccccocccccocconconcnononncnnnnnnnnnonncn nono nonnonncnnannc nan nn nannannns 5 32 INCLUDE supno LOCATION 200 raan a a a aaa a a aa a a E aN 5 33 INCLUDE supno MR RO R r a a a E aa a e A Ea e aE a a o laas 5 35 INCLUDE supno NOPRINT CHECK INCLUDE sesesesessesessesesetsssssesrsrtsessssesssrsessssesessesesees 5 36 INCLUDE supno PERFORM INCLUDE ssesseeeeseessseseeseseesesssstsessesesss
23. Refers to all but the previously selected tagged nodes see the TAG UNTAG commands Delete a lower level superelement that previously has been in cluded in the current higher level superelement The current su perelement cannot itself be part of an assembly The superelement number and index to be deleted Delete linear dependencies between nodes The linear depend encies of all selected dependent nodes are deleted Note that the dependent nodes and not the independent nodes are to be se lected Also note that this command will delete the LINEAR boundary condition of the dependent node It will also delete the SUPERL or SUPER boundary condition of the independ ent nodes unless other nodes still are linearly dependent on them Delete a load Delete a load combination for a higher level superelement Delete a nodal load for a higher level superelement See a spe cific description for this alternative below Delete a previously defined transformation The transformation number to be deleted SESAM Program version 7 3 DELETE LOAD NODE LOAD NODE Ic Presel 01 OCT 2004 5 19 SELECT select nodes TAGGED YES ALL UNTAGGED END NO FORCE SELECT select nodes PRESCRIBED DISPLACEMENT TAGGED Ha index UNTAGGED PRESCRIBED ACCELERATION END END PURPOSE The command deletes loads See the LOAD command for a more detailed explanation of the
24. The ratio between supernodes and internal free nodes should be as small as possible In practical terms this may be seen as making the superelements as compact in shape as possible e How to assemble the superelements to form the complete model some of the advice below will have bearing on how to split the structure into superelements Limit the number of higher level superelements and the number of levels Few and moderately large higher level superelements are better than many smaller ones For a large model this implies that the second level superelements will include many first level superelements the third level superelements will include many second level superelements and so on Be aware of that reduction of higher level superelements is time consuming A higher level superele ment will normally be much more time consuming than a first level superelement with the same number of internal and super nodes This is because the stiffness matrix of a higher level superele ment has few zeros and a large bandwidth Assemble superelements in an order corresponding to their topological sequence and not in a haphaz ard way Assemble superelements in the way Lego bricks are put together Avoid coupling one superelement with many other superelements Do not assemble superelements not geometrically coupled This concerns superelements belonging to the same structure 1 e their stiffnesses are coupled through other superele
25. Xy and Zy See Figure 5 10 PARAMETERS trano SpX Spy spz 8PX Spy gpZ La A Zg Second point global coordinates Transformation reference number Guiding point global coordinates YG v Xr lt gt SP gt X Figure 5 10 Definition of a transformed coordinate system SESAM Presel Program version 7 3 01 OCT 2004 5 81 UNTAG UNTAG select nodes PURPOSE The command untags in effect removes from a set some or all nodes for the purpose of referring to these nodes the UNTAGGED or to all other nodes the TAGGED in subsequent commands e g for defining boundary conditions Initially all nodes are untagged Nodes are tagged by the TAG command PARAMETERS select nodes Select nodes see Section 5 1 Presel SESAM 5 82 01 OCT 2004 Program version 7 3 WRITE WRITE supno PURPOSE The command writes Input Interface Files for the given superelement supno and all superelements in the hierarchy below supno except for the first level superelements which exist before the execution of Presel See Section 2 3 for information on the Input Interface Files SESAM Presel Program version 7 3 01 OCT 2004 5 83 ZOOM FRAME ZOOM IN OUT PURPOSE The command zooms in or out on the displayed picture The zoom buttons of the direct access button area have the same effect and are quicker in use see Section 3 1 However the ZOOM command diffe
26. briefly explained thereafter a small example tutorial is used to illustrate the procedure 3 2 1 Basic Procedure 1 Store all first level superelements in the Presel database by reading the SESAM Input Interface Files T files named T FEM Use the command READ This is optionally done automatically when starting Presel from the SESAM Manager select default Command input file 2 Create a new superelement assembly Use the command ASSEMBLY NEW This superelement is ini tially empty but it will become a second level superelement once a first level superelement has been included a Include a first level superelement in the new superelement assembly by the following process 1 Start the inclusion process by the command INCLUDE 2 If necessary translate rotate and mirror the first level superelement to its proper position in the assembly See the INCLUDE command for the alternative positioning commands 3 Verify graphically its position by the command DISPLAY 4 Check that the supernodes of the first level superelement match the nodes of the already included superelements if any Use the command NOPRINT CHECK INCLUDE 5 Complete the inclusion process by the command PERFORM INCLUDE 6 Verify the inclusion by the LABEL COUPLED NODES and other commands b Include other first level superelements by repeating the process above item a c When the assembly which has now become a second level superelement is complete then give appropriat
27. for the complete model Figure 3 9 takes you step by step through the commands for establishing the desired global loads Notes explaining the data to enter are also provided SESAM Presel Program version 7 3 01 OCT 2004 3 15 Load combinations for sup el 7 ASSEMBLY OLD 7 LOAD COMBINATION Define global load 1 glc sup indz llc factor 1 5 1 8 END 3 END END Define global load 2 2 Fix these two nodes for running analysis Global load 1 is defined Superelement 5 index 1 contributes with local load 8 with factor 1 0 END means that superelement 5 index 1 contributes with no more local loads to global load 1 Superelement 6 index 1 contributes with local load 3 with factor 1 0 to global load 1 END means that superelement 6 index 1 contributes with no more local loads to global load 1 END means that no more superelements will contribute to global load 1 it is now complete Global load 2 is defined Superelement 6 index 1 contributes with local load 4 with factor 1 0 and superelement 6 index 2 contributes with local load 3 with factor 2 0 No more global loads combinations are defined Figure 3 9 The commands and resulting loads If you at this stage want to continue the exercise by running the model through a structural analysis in Sestra you need to fix the model in space You may for example fix the two nodes along the X axis see the sketch in Figure 3 9 by giving the command BOUNDARY FIX FIX FIX FIX
28. including a superelement in the current superelement assembly See Sec tion 3 2 2 for a tutorial in how to use the INCLUDE command Initially the superelement being included will be position with its coordinate system overlapping the coordi nate system of the superelement assembly It may then be moved by repetitive use of the sub commands TRANSLATE ROTATE MIRROR and POSITION until it is properly positioned The sub command DIS PLAY will at any time show the current position of the superelement being included NOPRINT CHECK INCLUDE checks and tabulates the match of the nodes of the superelement being included and the current superelement CHECK INCLUDE does the same but produces more output It is mandatory to perform this check PERFORM INCLUDE performs and concludes the inclusion of the superelement in the current superele ment assembly The various INCLUDE sub commands listed above are explained in the following PARAMETERS supno Superelement number being included in the current higher level superelement Presel SESAM 5 26 01 OCT 2004 Program version 7 3 INCLUDE supno CHECK INCLUDE CHECK INCLUDE PURPOSE The sub command compares and tabulates the match between supernodes of the superelement being included and the nodes of the current superelement assembly The typical appearance of the table is shown in Figure 5 3 SUPER ELEMENT TYPE INCLUDE NODES SUP EL SUP EL EXT TYPE INDEX NO
29. is not influenced by whether the node numbering has been optimised to reduce the bandwidth of the stiffness matrix For the traditional Supermatrix solver however it is absolutely essential to minimise the bandwidth of the first level superelements stiffness matrices by optimising or re numbering their internal node numbering The auxiliary program Bpopt is used for this purpose in the case of Preframe the optimization is normally done inside the program When using the SESAM Manager optimization of first level superelements is controlled by Manager Note The optimization should be performed prior to reading the superelements into Presel Optimising higher level superelements may be done inside Presel using the command OPTIMIZE Note that a higher level superelement can only be optimised when it is complete i e when all relevant superelements have been included into it and before it is included in new higher level superelements The top level superelement may however be optimised after concluding the Presel session using the auxiliary program Bpopt Presel SESAM 3 44 01 OCT 2004 Program version 7 3 Provided the superelements are assembled into a higher level superelement an assembly in a logical brick on brick way as advised in Section 3 9 there is very little if anything to gain in terms of CPU reduction by optimising higher level superelements Using the OPTIMIZE command is therefore normally not necessary See Section 3 9 on
30. is required DEFINE SET creates a new set while CHANGE SET changes an existing set The command syntaxes of these two commands are identical and based on standard set operators Initially after giving the command DEFINE SET and entering a name the set is empty The first operation to do will therefore be to add to the set by the UNION WITH command Thereafter repetitive set operations may be performed until the content of the set is as desired The operations are executed consecutively the order of the operations are therefore of consequence Conclude the definition or changing of the set by entering END PARAMETERS setname User given name of the set to define maximum 8 characters and starting with a letter INTERSECTION WITH All nodes except those subsequently selected will be removed from the set I e the new contents will be the intersection be tween the current contents and the subsequent selection SUBTRACT BY The subsequently selected nodes will be removed from the set UNION WITH The subsequently selected nodes will be added to the set NODE Nodes are to be selected the only choice select nodes Select nodes see Section 5 1 SESAM Presel Program version 7 3 01 OCT 2004 5 17 DELETE ASSEMBLY supno SELECT select nodes TAGGED BOUNDARY UNTAGGED END supno index INCLUDED END DELETE SELECT select nodes TAGGED LINEAR DEPENDENCY UNTAGGED END COMBINATION gic LOAD NOD
31. level superelements and coupling matching supernodes e Combine loads for the assembly by referring to loads of the first level superelements Possibly also define some boundary conditions e Create higher level superelement assemblies combine loads and define boundary conditions in the same way as explained above only now include previously created superelement assemblies Repeat this proc ess until the complete analysis model has been created e Store all superlement assemblies the whole superelement hierarchy on file and exit Presel the storing is normally done automatically when exiting Presel This user s guide explains how to e Get started using the graphical user interface See Section 3 1 e Create the complete model by assembling superelements See Section 3 2 e Establish the loads for the complete model by combining loads on superelements See Section 3 3 e Assemble loads an alternative and advanced way of establishing the loads See Section 3 4 Define boundary conditions See Section 3 5 Define linear dependencies See Section 3 6 e Display and print data See Section 3 8 Presel SESAM 3 2 01 OCT 2004 Program version 7 3 e Use the superelement technique in a practical way to efficiently solve problems See Section 3 9 e Optimise node numbering reduce bandwidth of the stiffness matrix and when to do it See Section 3 10 3 1 Getting Started the Graphical User Interface Assuming you have sta
32. only contain the supernodes and these will be free nodes at assembly level Moreover if any of the nodes of the set are given the boundary condition super re defined as supernodes for the superelement assembly then the set containing these nodes will be available for yet a higher level superelement assembly Finally if two or more superelements have sets of supernodes with the same name then these will be merged at assembly level Note Sets defined in Prefem or Preframe containing only elements or geometry Prefem only will not be available in Presel as only nodes are relevant here Note The transfer and merging of sets of supernodes from superelements to superelement assem blies is only avaialble for named sets and not the predefined set TAGGED and UNTAGGED Presel SESAM 3 38 01 OCT 2004 Program version 7 3 3 8 Display and Print The DISPLAY CURRENT SUPERELEMENT command will display the current superelement This dis play may be refined by the SET GRAPHICS HIDDEN command plus two options under the SET GRAPH ICS PRESENTATION command FILLED ELEMENT and COLOUR SUPERELEMENTS All these three display modes may be used simultaneously Figure 3 26 shows an example of a display using the hidden option In addition to displaying the current superelement any superelement may be displayed without changing current superelement by the DISPLAY SPECIFIED SUPERELEMENT command This command is practi cal when you are working with assemb
33. optimised prior to being read into Presel See Prefem or Preframe on this If a superelement is to be optimised it must be done prior to being included in a higher level superelement assembly See Section 3 10 for more information PARAMETERS supno Superelement number BANDWIDTH The internal node numbering is optimised to reduce the bandwidth of the stiffness matrix This is the preferred option for Sestra OPTIONS This alternative is currently irrelevant PROFILE The internal node numbering is optimised to reduce the profile of the stiffness ma trix This alternative is currently irrelevant Presel SESAM 5 58 01 OCT 2004 Program version 7 3 PLOT AS LAST DISPLAY PLOT text 4 page size choices Where choices in the command syntax above represents all of the following ALL NODES Mesh on plot Origin symbol Boundary conditions YES or NO YES or NO YES or NO BEES NRE eer NONE COUPLED NODES NON COUPLED NODES EXTERNAL NODE NUMBER supno_ index INTERNAL NODE NUMBER supno index NODE NUMBER TRIPLET ONE NODE NUMBER TRIPLET ALL NODE NUMBER TRIPLETS NONE PURPOSE The command reproduces the display on a plot file or sends it directly to the printer in case of WINDOWS PRINTER format of the plot file Unless the AS LAST DISPLAY option is chosen the command poses the following questions Includ
34. that some operating systems change the case of the input text if it is not enclosed in quotes Slanted arguments or values indicate that these are defaults Presel SESAM 4 6 01 OCT 2004 Program version 7 3 e If at least one of the arguments PREFIX NAME and STATUS is specified then the prompt for data base and journal file name is skipped and defaults are used for any unspecified values The values given to the EYEDIR are real values The default is the Presel default values If one of the three are given the other two are set to 0 0 unless specified In some cases a virtual screen larger than the real screen is used In such cases reduce the WINDOW SIZE argument value 4 2 Program Requirements 4 2 1 Execution Time The execution time required is negligible for most commands A few commands however will require some CPU and should be used with care on low capacity computers An example of this is a display with hidden option 4 2 2 Storage Space The initial size of the data base prior to any modelling is less than 2 MB 10 20 MB will be sufficient for most models 4 3 Program Limitations Graphics Devices The graphical user interface is implemented on Microsoft Windows Other devices are currently not used Memory Presel allocates memory buffers for access to data of the data base file When using the graphical user inter face Presel will allocate memory for the display File access buffer The me
35. the size specification within the PLOT command is used Presel SESAM 5 76 01 OCT 2004 Program version 7 3 SET PRINT FILE DESTINATION SCREEN LINEPRINTER FILE NAME filnam E FORMAT F PRINT G FILE PAGESIZE nlines SCREEN DIGITS NODE BOUNDARY TABLE TABLE TEXT SUPER ELEMENT HIERARCHY width PURPOSE The command sets different parameters controlling the execution of the PRINT command PARAMETERS DESTINATION FILE LINEPRINTER NAME filnam FORMAT PAGESIZE Destination of print is set to FILE or SCREEN This setting overrules the default destination which varies depending on what to print However the commands PRINT ALL and PRINT supno will always send their output to file because of the anticipated large amount of output Decide the name of the print file The default name is the same as the model and command log file name The file extension is LIS This option has presently no function Set the print file name to filnam Select between E F and G FORTRAN format for printing real numbers F is the default selection Very large real numbers cannot be printed in F format the user may in such cases select E or G Decide number of lines printed for each page The table head ing is repeated for each page SESAM Presel 01 OCT 2004 5 77 Program version 7 3 FILE SCREEN nlines TABLE NODE BOUNDARY TABLE SUPER ELEMENT
36. to be selected either after the line mode option SINGLE or inside any of the other options the node may be clicked as an alternative to typing in the node number triplet 5 1 3 Command Syntax for Node Selection Whenever selecting nodes is required the command syntax is GLOBAL COORDINATES USE COORDINATE SYSTEM coord name supno index nodeno SINGLE supno index nodeno GROUP supno index nodel node2 nstep SEGMENT LINE point 2 INFINITE 3 PLANE point 3 PLANE 2 PLANE point 2 VOLUME point 2 SET setname ALL END Where point in the command syntax above represents specifying a point as follows NODE supno index nodeno COORDINATE x y Z LOCAL COORDINATE r phi Z The LINE PLANE and VOLUME alternatives offer selection by referring to points in space These lines planes and volumes may be interpreted in the cartesian coordinate space of the superelement the GLO BAL COORDINATES option or in a cylindrical coordinate space the USE COORDINATE SYS TEM option Figure 5 1 illustrates this Such a cylindrical coordinate system must previously have been defined by the COORDINATE SYSTEM command You may switch back and forth between these two spaces within the same selection sequence i e before giving END The space chosen last is valid for the subsequent LINE PLANE and VOLUME commands If neithe
37. to form the complete model to be analysed 2 1 Basic Features and Principles Presel reads the first level superelements from the Input Interface Files These files are named T FEM where is the superelement number an identification of the superelement The first level superelements may be displayed and given names but not modified in any way Ifa first level superelement need to be modified you have to revert to the preprocessor that created it e g Prefem or Pre frame A first level superelement cannot be modified once it has been read into Presel Higher level superelements are created in Presel A higher level superelement contains no nodes and ele ments until one or more superelements have been included into it A higher level superelement is given con tents by including first level superelements and or previously created higher level superelements There are no restrictions as to the number of superelements that may be included in an assembly Superelements at any level may be included in the same assembly The assembly will implicitly be assigned a superelement level equal to the highest level among its included superelements plus one For example if the highest level among the included superelements is three then the assembly will be a level four superelement Boundary conditions like supernodes and fixations as well as loads are defined for higher level superele ments assemblies The loads will normally be combinations of loads pre
38. to use the latter as it is more consistent with the other SET PLOT commands Note that the command closes the current plot file if such exists en abling this to be sent to a laser printer without having to exit Presel Prefix of the plot file Name of the plot file Set the draw mode for elements and superelements Switch colouring of superelements ON and OFF Note that dif ferent occurrences of the same superelement number will have the same colour The default is OFF Switch filling of elements with a light blue colour ON and OFF The default is OFF Switch ON and OFF automatic scaling of the displayed su perelement to fit the graphic display area The default is ON Shrink the display of the basic elements Shrink factor Specify the sizes of the symbols appearing on the displayed picture and the plot The symbol sizes are given in mm Symbols for boundary conditions will be re sized to the given value Load factors printed on top of the colour coded superelements by the DISPLAY LOAD FIRST CONTRIBUTING LOAD SESAM Presel Program version 7 3 01 OCT 2004 5 73 NEXT CONTRIBUTING LOAD commands will be re sized to the given value NODE NUMBERS Node number triplets will be re sized to the given value NODE SYMBOLS Symbols for the nodes will be re sized to the given value ONE NODED ELEMENT SYMBOLS Symbols for one node elements will be re sized to the given value These are the elements connected to only one node i e
39. used SET ELEMENT TYPE SURFACE ALL SURFACES INCLUDED SHELL 8NODES Define fixations and supernodes PROPERTY BOUNDARY CONDITION AJ amp amp 1l ATE amp amp l1 FIX FIX FIX FIX FIX FIX GLOBAL AJ amp amp 2 AT amp amp 2 SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE GLOBAL Define thickness PROPERTY THICKNESS ALL SURFACES INCLUDED 0 1 Define and connect material PROPERTY MATERIAL CONCR ELASTIC 0 3E11 0 25 2500 0 O CONNECT MAT o M Gl Define lin e load PERTY LOAD 1 GRAVITY GLOBAL RIAL CONCR ALL SURFACES INCLUDED END FLEXIBLE PART END Create mesh ms ES The model is now complete H ALL Exit Prefem CONTRIBUTION 0 0 9 81 HP Je A 2 2 Superelement 2 Prefem input for creating superelement number 2 the long wall JP AP AP AP G EN First crea ERATE CARTES 700 SURFACE END te geometry IAN 0 0 0 8 0 0 3 END A12141212 END SESAM Program version 7 3 SESAM Presel Program version 7 3 01 OCT 2004 APPENDIX A 5 Then select 8 node shell element to be used T SET ELEMENT TYPE SURFACE ALL SURFACES INCLUDED SHELL 8NODES T Define supernodes PROPERTY BOUNDARY CONDITION ALL LINES INCLUDED SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNOD GLOBAL
40. 01 OCT 2004 DISVA AOON Xopul quowajosodng LSIOISVA YOO TA LSTHLYON TIVMT y Xopur p Xopul 7 1uauuajaladng y 1Uaua aladng LSIHLAOS TIVAT 7 1uawapoadng LSIHLHON TIV MS p xopul g qoulsjosodng ISIHLNOS TIVMS g 1uawoapoladng AHYUO LS T xoput 01 1uawuajaradng CRIDOIS VA AOOTA CMHDHLAON TIVMT xoput z x pur Xoput ASAOH xX pur 001 wWauajesodng p 1uouo asadng 7 Wawojoodng 7 qowajosodng CYOHLYON TIVMS CYDHLAOS TIVMS T xoput 1 x pu g 1uowpoladng g qoulsjosodng AHYOLS xopur or jewayorodng CYOH LNOS TIVMT OISVE LUNA xepul quowiayorodng Figure 3 20 Superelement hierarchy for the house model SESAM Presel Program version 7 3 01 OCT 2004 3 31 3 4 3 Tutorial in Using the LOAD ASSEMBLY Command The tutorial below takes you step by step through the commands for assembling the loads for the example of Section 3 4 2 The loads are illustrated in Figure 3 21 Load 5 people and furniture on floors there is 50 more people and furniture in Load 4 weight of snow on roof ground floor than in first floor Figure 3 21 Loads on the house model The five loads to be created for the house are Load case 1 Self weight gravity of the house Load case 2 Wind pressure on south walls both long and short walls Load case 3 Wind pressure on south long walls and north short walls Presel SESAM 3 32 01 OCT 2004 Program versio
41. 1 5 2 will define loads 1 3 and 5 STEP A step increment in numbering of the local load cases of the included superele ments 1s to be given see incr below If this command is omitted then incr is omitted as well SESAM Presel Program version 7 3 01 OCT 2004 5 53 lowllc The lowest local load case number of the included superelement contributing to glc incr The step increment in local load case numbering Presel SESAM 5 54 01 OCT 2004 Program version 7 3 LOAD NODE FORCE NODE lc PRESCRIBED ACCELLERATION PRESCRIBED DISPLACEMENT SELECT _ select nodes TAGGED UNTAGGED END GLOBAL fx fy fz mx my mz TRANSFORMTAION trano IMAGINARY COMPLEX ifx ify ifz imx imy imz PHASE COMPLEX pfx pfy pfz pmx pmy pmz END PURPOSE The command defines nodal loads for the current superelement The current superelement must be a second or higher level superelement The nodal loads are of the following types Forces and moments the FORCE alternative e Prescribed displacements e Prescribed acceleration relevant for dynamic analysis only Prior to giving prescribed displacements and accelerations the corresponding nodes must previously have been given the PRESCRIBED boundary condition see the BOUNDARY command Alternatively to all six only selected d o f s may be given prescribed displacements accelerations The PRESCRIBED
42. 1 OCT 2004 5 11 CHANGE LINEAR DEPENDENCY LOAD SET TRANSFORMATION CHANGE PURPOSE The command changes data previously defined The CHANGE LINEAR DEPENDENCY and CHANGE LOAD commands are described in more detail in the following The CHANGE SET and CHANGE TRANSFORMATION commands however have identical syntax with the commands defining the data Refer to the DEFINE SET and TRANSFORMATION commands for details Presel SESAM 5 12 01 OCT 2004 Program version 7 3 CHANGE LINEAR DEPENDENCY LINEAR DEPENDENCY a dep node triplet dep dof indep node triplet indep dof beta PURPOSE The command changes linear dependencies between nodes Only the linear dependency factor beta may be changed The linear dependency may originally have been defined by either the GENERAL NODE DEPENDENCY or the TWO NODE DEPENDENCY option see the LINEAR DEPENDENCY com mand PARAMETERS dep node triplet Node number triplet supno index nodeno previously defined as dependent dep dof D o f previously defined as dependent of the indep dof of the indep node triplet choose either X Y or Z Translations in X Y or Z directions R X R Y or R Z Rotations about the X Y or Z directions indep node triplet Node number triplet supno index nodeno previously defined as independent the one being supernode indep dof D o f previously defined as independent
43. 3 3 3 4 Table of Contents INTRODUCTION cwciscecensccasuccsenuadecs vassueansecotetosnesescuecdeveseedubececsvcnosdnetessietveauatekvaceevacs saksaders 1 1 Presel Preprocessor for Assembling SuperelementS o coooninconococonononononconnconncnnoconnonn cono noo nncinanass 1 1 Preselinthe SESAM yt aa idas 1 3 Howto read the Manuals ti title 1 4 SEALS TEAS O ON 1 4 FEATURES OF PRESEL ssesessecsssoosssossosssssosssocsssossoessseossoesssossosssocossscesssosssossosssssooss 2 1 Basic Features and Principles cit di a aida 2 1 Short Description of Commands ccccccscesccesscessessseeseceseeseceeecessecseecseceaeeseseaeesaecaaeceeesenesenecsaeeaeees 2 2 Transfer of the Model through the Input Interface File oooonccinnoncncnncnoncnncnncnncnncncnro nac nancnncnncnnos 2 3 USER S GUIDE TO PRES Bd oieccccsinnascccscsssseussesccsaseuecssetieetoss oseucssevoaeds esas canceqvovecseuateedun 3 1 Getting Started the Graphical User Interface cccccccecessceecesceesceeseceseceeeeseeeacensecnsecneeeeneenaes 3 2 Assemble Superelement ivf caste B cess Ac id tit tte t abate 3 5 3 241 Basic POC a ia 3 5 3 2 2 Tutorial in Assembling Superelement 0 0 0 0 cccecccesceeceeceeceeseececeeeeseeeseeaeceaeseeeenneeeaes 3 6 32 3 Auxiliary Commands Ina aa ea saeta dolia 3 10 3 2 4 Identifying Superelement Occurrences oooocccoccoonnoonconnconnconncono con nonnncon noo nn connnnnrrnn nro nacnnanos 3 10 3 2 5 Identifying Nodes in a Superelement Model
44. 6 0 F Presel SESAM 3 20 01 OCT 2004 Program version 7 3 END END etc for each global load case up to the last one 96 3 1 96 1 0 END 6 1 191 1 0 is END 6 2 192 1 0 END END END END Note The asterisk above indicates lines of input deviating from the corresponding Wajac input As can be seen the one by one method involves a lot of input 24 times the amount given above even for such a small superelement hierarchy For a large superelement hierarchy the amount of input will increase many times The group method involves considerably less input lowglc higlc step sup indx lowllc incr factor LOAD COMB GROUP 1 96 1 5 dl 1 1 0 6 1 STEP 1 2 1 0 6 2 STEP 2 2 1 0 END END END This command says that global load cases 1 to 96 with step 1 will be created The superelement occurrences sup indx 5 1 6 1 and 6 2 will contribute to these global load cases For each occurrence only the local load case lowllc corresponding to the first global load case is given i e 1 1 and 2 for the three occur rences respectively The command STEP given prior to the lowllc for occurrences 6 1 and 6 2 means that the local load case is incremented by the value incr 2 for each increment of 1 of the global load case Notice that STEP is not given for occurrence 5 1 and neither is an incr value this is because superelement 5 occurs only once Note The STEP command
45. A AFB C xx X De X AFX AX X Y Z SESAM 01 OCT 2004 Program version 7 3 replaces A by X in all strings beginning with A replaces A by X in all strings ending with A replaces A by X in any string containing A appends X to all strings appends X to all strings beginning with A appends X to all strings ending with A replaces the characters A B and C in strings containing these charac ters e g ABC ABIC A12B34C by X Y and Z respectively SESAM Presel Program version 7 3 01 OCT 2004 5 35 INCLUDE supno MIRROR YZ PLANE MIRROR ZX PLANE XY PLANE PURPOSE The sub command mirrors the superelement being included about one of the three planes defined by the axes of the superelement assembly Z ewe Y ESTO F poe i 1 X i a E 1 r 1 1 L 1 Position before mirroring Position after mirroring Figure 5 6 MIRROR about ZX PLANE NOTES It is the current position of the superelement being included that is mirrored Mirroring a superelement involves that the superelement occurrence gets a left handed coordinate system The results must then be interpreted in such a coordinate system Mirroring a superelement twice e g by also mirroring the superelement assembly when this in turn is included in yet a higher level superelement involves that the superelement occurrence regains a right handed coordinate system Presel SESAM 5 36 01 OCT 2004 Program version 7 3 INCLU
46. AD COMBINATION NODE PURPOSE The command defines loads for the current superelement which must be a second or higher level superele ment The three alternatives are described in more detail in the following PARAMETERS ASSEMBLY This option allows assembling loads directly to the top level See Section 3 4 for more information on this COMBINATION This option creates a load for a superelement assembly by combining loads of its included superelements NODE This option creates nodal loads SESAM Program version 7 3 Presel 01 OCT 2004 5 51 LOAD ASSEMBLY INCLUDE LOAD refname refloc local load case factor ASSEMBLY glc top END PURPOSE The command defines loads for the current superelement assembly normally the top level superelement by combining loads of lower level superelements normally 1st level superelements The lower level superele ments are referred to by names and location strings Load combinations are automatically created for all intermediate level superelements The use of the command is explained in Section 3 4 The load combinations created for the current superelement assembly and all intermediate level superele ments may be verified by the PRINT LOAD command PARAMETERS glc top INCLUDE LOAD refname refloc lle factor Global load case number of the superelement assembly Include in the global load case the following lower level sup
47. DE supno NOPRINT CHECK INCLUDE NOPRINT CHECK INCLUDE PURPOSE The sub command compares the supernodes of the superelement being included and the nodes of the current superelement assembly It has the same purpose and functionality as the NOPRINT CHECK INCLUDE sub command except for that the table over matching nodes is omitted Only the summary information is glven see Figure 5 3 SESAM Presel Program version 7 3 01 OCT 2004 5 37 INCLUDE supno PERFORM INCLUDE PERFORM INCLUDE PURPOSE The sub command concludes the process of including a superelement in an assembly It is given subse quently to the sub command NOPRINT CHECK INCLUDE or CHECK INCLUDE The following table is produced SUPER ELEMENT INCLUDED SUPER ELEMENT TYPE dh SUPER ELEMENT INDEX 3 LEVEL a NO OF INTERNAL NODES 2 NO OF SUPER NODES MATCHING 3 NO OF SUPER NODES NOT MATCHING 3 NO OF NODES 8 INTO SUPER ELEMENT ASSEMBLY SUPER ELEMENT TYPE 2A SUPER ELEMENT INDEX 1 LEVEL 2 NO OF OLD NODES 9 NO OF NEW NODES 3 NO OF NODES 12 NOTES The command is the mandatory final step in including a superelement in an assembly Presel SESAM 5 38 01 OCT 2004 Program version 7 3 INCLUDE supno POSITION NODE supno index nodeno POSITION 6 COORDINATES x y Z PURPOSE The sub command positi
48. E END TRANSFORMATION trano PURPOSE The command deletes data previously defined Only the DELETE LOAD NODE command is described in detail in the following Notes are given below for the other alternatives Otherwise see the commands defin ing the data PARAMETERS ASSEMBLY Delete an assembly normally a higher level superelement A first level superelement may however also be deleted with the effect that it will be as if the superelement had not been read into Presel All data relating to the superelement are deleted The superelement to delete cannot be part of a higher level su perelement i e it cannot have been included in any assembly supno Superelement number to be deleted BOUNDARY Delete boundary conditions for the current superelement which must be a higher level superelement 1 e boundary conditions cannot be deleted for first level superelements The selected nodes will then be FREE for all d o f s Note that the boundary conditions LINEAR and SUPERL see the LINEAR DE Presel SESAM 01 OCT 2004 Program version 7 3 5 18 SELECT select nodes TAGGED UNTAGGED INCLUDED supno index LINEAR DEPENDENCY LOAD COMBINATION NODE TRANSFORMATION trano PENDENCY command can only be deleted using the DE LETE LINEAR DEPENDENCY command Nodes are to be selected now Select nodes see Section 5 1 Refers to previously selected tagged nodes see the TAG UN TAG commands
49. E supno index nodeno DISTANCE CHEKC 2 COORDINATE x y Z PURPOSE The sub command computes and prints the distance between a node or point in the superelement assembly and the corresponding node or point in the superelement being included The node point of the superelement assembly is given first If the COORDINATE alternative is chosen the point does not have to correspond to a node The coordinates are given in the coordinate systems of the assembly and superelement being included respectively PARAMETERS NODE Refer to a node triplet supno index nodeno The node number triplet COORDINATE Refer to a point by using coordinates XyZ The point coordinates Presel SESAM 5 32 01 OCT 2004 Program version 7 3 INCLUDE supno END DO NOT INCLUDE END DO NOT INCLUDE PURPOSE The sub command aborts the inclusion process of the superelement and prepares for including another superelement To merely discard the given transformations of the superelement currently being included use the RESET T MATRIX command SESAM Presel Program version 7 3 01 OCT 2004 5 33 INCLUDE supno LOCATION CHANGE oldloc newloc CREATE loc LOCATION USE refloc modloc DELETE oldloc PURPOSE The sub command is used in connection with the LOAD ASSEMBLY command It creates and modifies location strings for superelements being included See Section 3 4 for an explanation of asse
50. EAR linearly dependent of some other d o f s 4 SUPER super d o f 100 SUPERL super d o f due to linear dependency COORDINATES Print coordinates for selected nodes See example print in Sec tion 3 8 LINEAR DEPENDENCY Print linear dependencies for selected nodes NUMBER Print the node numbers of selected nodes The table shows the node number triplets along with the internal node numbers SELECT Nodes are to be selected now SESAM Presel Program version 7 3 01 OCT 2004 5 65 select nodes Select nodes see Section 5 1 TAGGED Refers to previously selected tagged nodes see the TAG UN TAG commands UNTAGGED Refers to all but the previously selected tagged nodes see the TAG UNTAG commands Presel SESAM 5 66 01 OCT 2004 Program version 7 3 READ supno SHOW PROGRESS _ supno READ PURPOSE The command reads a first level superelement into Presel s database That is the Input Interface File of the superelement is read The Input Interface File must have the following name also see Section 2 3 prefixTsupno FEM Note When using the SESAM Manager to control your analysis the prefix will normally be void Note The prefix is given when starting Presel This means that if the Input Interface File has a pre fix then this prefix must be given at start up Also note that the Input Interface File names of all first level superelements must have the same prefix PARAME
51. FIX FIX GLOBAL SELECT LINE INFINITE COORDINATE 0 0 0 COORDINATE 1 0 0 END Then leave Presel by clicking EXIT If you do not use Manager you must give the command WRITE 7 before exiting Presel to produce the T7 FEM file for top level superelement 7 If you do use Manager you must have checked Write top level superelement on exit when starting Presel The model is now com plete and may be analysed using Sestra and the results may be presented by Xtract If you are a new user you may at this stage want to learn about the effect on loads of rotating and mirroring superelements by reading Section 3 3 3 Other sections of interest to the new user are Section 3 5 Boundary SESAM 01 OCT 2004 Program version 7 3 Presel 3 16 Conditions Section 3 8 Display and Print and Section 3 9 Practical and Efficient Application of the Superelement Technique 3 3 3 Effect on Loads of Rotating and Mirroring Superelements If a superelement is rotated and or mirrored when being included in a superelement assembly its loads are rotated and or mirrored too This is exemplified in Section 3 3 2 where load 3 on superelement 6 see Figure 3 8 is rotated and multiplied by 2 when being combined into global load 2 of top level superelement 7 see Figure 3 9 A mathematical explanation of this is found in Appendix B THEORY Section B 1 3 Figure 3 10 illustrates this A B and C are loads that rotate or mirror with the superelement to new po
52. G tags selected nodes These may subsequently be referred to as TAGGED within for example the BOUNDARY command TASK switches to input mode for Submod see the Submod User Manual In most cases you will find it more convenient to ac cess Submod directly rather than through Presel TRANSFORMATION defines transformations that can be referred to when defining loads and boundary conditions UNTAG resets node tags WRITE writes Input Interface Files for higher level superelements See Section 2 3 on this ZOOM increases or decreases the scale of the display reads commands from a command input file defined by the SET COMMAND INPUT FILE command DELETE deletes data EXIT exits from Presel The model and log files are saved and closed 2 3 Transfer of the Model through the Input Interface File As is the case for all SESAM preprocessors the model created by Presel is transferred to the hydrodynamic and or structural analysis programs via the Input Interface File which forms a part of the SESAM Interface File system Figure 2 1 illustrates this transfer of models between the preprocessors and the analysis pro grams The Input Interface File the T file is a sequential ASCII character file with 80 character long records The straightforward definition of the file enables external programs to be connected to the SESAM system with comparative ease One interface file will be created for each superelement The name of the file will be pre
53. IX A TUTORIAL EXAMPLES In order to perform the tutorial examples of Chapter 3 some superelements created by Prefem are required The inputs for these are presented in the following A1 The Tutorials in Assembling Superelements and Combining Loads In the tutorial example of Section 3 2 2 and Section 3 3 2 the two first level superelements 5 and 6 are assembled into the second and top level superelement 7 The Prefem inputs required for creating superele ments 5 and 6 are provided below Having created these two superelements you will be able to perform the Presel tutorials free nodes are diamonds yellow on screen 7 ox node numbers Y 3 ar CY 2 lt gt a a supernodes are circles 4 blue octagons on screen Figure A 1 The two first level superelements 5 and 6 created by Prefem A 1 1 Superelement 5 ae o Prefem input for creating superelement number 5 Presel SESAM APPENDIX A 2 01 OCT 2004 Program version 7 3 Semicolons are used to accept default values JP AP Ae oP First create geometry GENERATE SURFACE A 1 2 1 4 1 2 1 2 END CARTESIAN 0 0 0 400 END 0 3 0 END Adjust number of elements to be created along lines SET NUMBEROF ELEMENTS AI11 AJ21 3 o l l l 4 node shell element to be used SURFACE ALL SURFACES INCLUDED SHELL 4NODES Then selec SET ELEMENT TYP I oct o l l l
54. If a superelement is to be rotated or mirrored then either all three translational d o f s or all three rotational d o f s or all six d o f s must be super The reason for this is explained in Appendix B THEORY Section B 1 3 Note Nodes to couple must have equal sets of super d o f For example both may have all 6 d o f as super which is the most common case or both may have the translations in x and y and rota tion about z as super etc In Presel commands like BOUNDARY LOAD PRINT and TAG you need to select nodes Section 5 1 explains how this is done SESAM Presel Program version 7 3 01 OCT 2004 3 13 3 3 Combine Loads This section explains how to establish the loads for the complete model by combining loads for higher level superelements The motivation for combining loads is first explained in Section 3 3 1 and thereafter exem plified in Section 3 3 2 employing the tutorial of Section 3 2 2 There are three alternative methods for combining loads LOAD COMBINATION one by one This is the basic and explicit method for combining loads it is exemplified in Section 3 3 2 LOAD COMBINATION GROUP group of loads For models comprised of several superelements and a number of load cases the one by one method will involve a considerable amount of input If all superelement occurrences have the same number of loads numbered from 1 and up as is the case e g for an offshore structure subjected to
55. Jomin 3 3 2 superelement 100 superelement index Figure 3 30 PRINT SUPER ELEMENT HIERARCHY SESAM Presel Program version 7 3 01 OCT 2004 3 41 Table shows coordinates for this superelement SUPER ELEMENT TYPE 10 LEVEL 2 SUP EL SUP EL EXT INT COORDINATES BOU TYPE INDEX NO NO X Y Z ND 17 45 9840 000000 0 000000 0 000000 X6 18 gt 46 9840 000000 0 000000 616 666687 X6 37 47 10840 000000 1680 000000 0 000000 6 9840 000000 9840 000000 000000 1233 333374 X6 000000 1850 000000 X6 oo If a node has more than one triplet N BOU means boundary conditions ND means number all will be listed of d o f s X means the node has a boundary condition This node has two triplets use PRINT NODE BOUNDARY CONDITIONS for this node has one details 6 means this node has 6 d o f s The INT NO PRESEL s internal node number is normally of little interest Figure 3 31 PRINT NODE COORDINATES 3 9 Practical and Efficient Application of the Superelement Technique The theoretical foundation for the superelement technique puts few if any limitations on how to split the structure into superelements and how to put these together to form the complete model However the numerical accuracy of the results and above all the consumption of computational time and disk space are influenced by such choices There are several aspects of how to apply the superelement technique in an optimal way and an i
56. L The model is now complete Exit Prefem o A END MIDDLE SURFAC 0 9 81 E A 2 5 Superelement 5 Ao Je SESAM Program version 7 3 01 OCT 2004 Prefem input for creating superelement number 5 Presel APPENDIX A 7 the roof JP AP Ae ye First create geometry GENERATE SURFACE A 1 2 1 4 Do Wy S250 VD 2 CARTESIAN 0 0 0 7 O END 0 4 0 END O 2 0 9 END DELETE GEOMETRY AU AS AT121 AI122 AJ112 AJ212 CHANGE LINE AK121 AP121 AP112 2 AK221 AP221 AP212 2 DELETE GEOMETRY AP122 AP222 DEFINE SURFACE AS111 AK111 AK121 AJ111 AS211 AK211 AK221 AJ211 AT121 AI121 AK121 AI112 AK221 Then select 8 node shell element to be used SET ELEMENT TYPE SURFACE ALL SURFACES INCLUDED SHELL 8NODES Define supernodes PROPERTY BOUNDARY CONDITION AJ amp amp l AI amp amp l1 SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE SUPERNODE GLOBAL Define thickness PROPERTY THICKNESS ALL SURFACES INCLUDED 0 03 Define and connect material PROPERTY MATERIAL CONCR ELASTIC 0 3E11 0 25 2500 0 O CONNECT MATERIAL CONCR ALL SURFACES INCLUDED END Define loads PROPERTY LOAD 1 GRAVITY GLOBAL FLEXIBLE PART CONTRIBUTION 0 0 9 81 END LOAD 2 COMPONENT PRESSURE AT
57. L STEEL ELASTIC CONNECT MATERIAL STEEL ALL SURFACES INCLUDED END Define line loads PROPERTY LOAD 3 LINE LOAD AJ11 GLOBAL 1 5 0 0 PROPERTY LOAD 4 LINE LOAD AI12 GLOBAL 0 3 0 0 o Create mesh MESH ALL The model is now complete Exit Prefem o o A2 The Tutorial in Assembling Loads In the tutorial example of Section 3 4 2 and Section 3 4 3 the five first level superelements 1 through 5 are assembled to form the top level superelement 100 The Prefem inputs required for creating these first level superelements are provided below Having created these superelements you will be able to perform the Pre sel tutorials Y X superelement 1 foundation name is FNDT superelement 2 long wall superelement 3 short wall name is LWALL name is SWALL X superelement 4 floor superelement 5 roof name is FLOOR name is ROOF Figure A 2 The first level superelements 1 2 3 4 and 5 created by Prefem Presel APPENDIX A 4 A 2 1 Superelement 1 01 OCT 2004 Prefem input for creating superelement number 1 the foundation od AP AP AP First crea te geometry GENERATE SURFACE A1 21412121211 CARTESIAN 0 0 0 7 0 0 END O0 4 0 END O O 0 8 END DELETE GEOMETRY AU Then select 8 node shell element to be
58. N 5 61 Print on screen information on nodes The com mand is described in detail in the following Print on screen an overview of all superelements See example print in Section 3 8 Print on screen model and log file names and cur rent tolerances Print on screen the superelement hierarchy up to the given superelement supno index See exam ple in Section 3 8 Print on screen information transformations de fined for the current superelement Select one or all transformations Give END to stop printing transformations Presel SESAM 5 62 01 OCT 2004 Program version 7 3 PRINT LOAD ALL TYPES NODES COMBINATIONS COMBINATIONS Ic NODE FORCE NODE PRESCRIBED LOAD END ALL LOADCASES Ic OVERVIEW ALL LOADCASES END SELECT _ select nodes TAGGED UNTAGGED END PURPOSE The command prints loads defined for the current superelement PARAMETERS Ic Load case number ALL TYPES NODES COMBINATIONS Print all types of loads for the selected load case number COMBINATIONS NODE FORCE NODE PRESCRIBED SELECT select nodes TAGGED Print only the load combinations belonging to the selected load case number Print only the nodal forces for selected nodes belonging to the selected load case number Print only the nodal prescribed displacements and accelera tions for selected nodes belonging to the selected load case numbe
59. OBAL AXIS Y AXIS degrees Z AXIS X AXIS ROTATE OBJECT AXIS Y AXIS degrees Z AXIS NODE supno index nodeno ARBITRARY AXIS 2 degrees COORDINATES x y Z PURPOSE The sub command rotates the superelement being included an angle about a specified axis A positive angle is defined by the right hand rule Position after rotation Figure 5 8 ROTATE about global axes PARAMETERS GLOBAL AXIS The superelement being included rotates about one of the coordinate axes of the su perelement assembly OBJECT AXIS The superelement being included rotates about one of the coordinate axes of the su perelement itself Presel 5 42 X AXIS Y AXIS Z AXIS ARBITRARY AXIS NODE supno index nodeno COORDINATE xyz degrees 01 OCT 2004 The axis of rotation The axis of rotation The axis of rotation SESAM Program version 7 3 The superelement being included rotates about an axis defined by two points The axis points from the first to the second point which then determines the positive di rection of rotation the right hand rule The points are given by referring to nodes or by giving coordinates in the coordinate system of the superelement assembly Refer to a node triplet The node number triplet This node must be a part of the current assembly i e be long to a superelement that has previously been included Refer to a point by using coordinates The point coordinates Rotation given in degrees
60. OFORCED EXIT EYEDIR X value EYEDIR Y value EYEDIR Z value WINDOW SIZE value Presel 01 OCT 2004 4 5 General file name Data base journal file status Start the program in line mode Start the program in graphical user interface mode Do not show the program header Do not show the program header Show the standard program header Write an Input Interface File with the given top level su perelement number plus all lower level superelements when exiting the program Do not write an Input Interface File Read the specified command input file after the model journal file has been accepted Do not read a command input file Force EXIT after initialisation and after processing of the file defined by the COMMAND FILE argument Disable FORCED EXIT Set initial eye direction X value Set initial eye direction Y value Set initial eye direction Z value Set height of the graphic mode window width is determined based on height The value 100 corresponds to full height of the screen Default value is 90 Note the following about how to enter the command line arguments Command line arguments and values can be abbreviated Each argument name must begin with a slash and each argument value must be preceded by an equal sign Spaces can freely be distributed around the equal sign and before each slash e Texts with blank spaces and special characters e g file names must be enclosed in quotes Note
61. OUTHGRD n for the north walls NORTH NORTHGRD 10 NOPRINT CHE odify loca LOCATION US Modify loca S a o H O o LOCATION U odify loc n for the floor LOCATION USE BASIC BASICGRD PERFORM INCLUDE PE Ck La Gt P O H O Ao Gl o 10 TRANSLATE 0 0 3 NOPRINT CHECK INCLUDI Modify locations for all using wild card LOCATION USE 1ST E o Presel SESAM 3 28 01 OCT 2004 Program version 7 3 PERFORM INCLUDE TRANSLATE 0 0 6 8 NOPRINT CHECK INCLUDE L P OCATION CREATE BASIC ERFORM INCLUDE END For the first inclusion of superelement 10 the location strings are modified one by one The two superele ment occurrences LWALL and SWALL having location string SOUTH get the new string SOUTHGRD the two occurrences having location string NORTH get the new string NORTHGRD and the single occur rence having location string BASIC gets the new string BASICGRD But when all superelement occurrences shall have the same string added to their locations as in this case a wild card notation can be used as shown for the second inclusion of superelement 10 The foundation 1 and roof 5 superelements are included for the first time the LOCATION CREATE command is used for these They are given location strings BASIC as no specific identifications are required Note If you give location strings also for higher level superelem
62. Program version 7 3 01 OCT 2004 3 23 Notice the sequence 1 111 2 Lashed of the indexes 2 21 1 a Diol lid ea N 1 2 12 1 3 21 2 1 2413S 2 12 2 Presel s table Manual sketch Figure 3 15 Incorrect superelement hierarchy 3 Proper Superelement Hierarchy Figure 3 16 shows a superelement hierarchy avoiding the problem described above Superelement 21 is cre ated first Thereafter superelement 31 is created including superelements in the following order 21 21 and 11 at the end 1 31 1 1 21 1 Lee T 2 12 1 2 21 2 ae oe ea 2 12 2 1 2 1 2 aii sus y ej yu ej a Presel s table Manual sketch Figure 3 16 Proper superelement hierarchy 3 4 Assemble Loads When using the LOAD COMBINATION command explained in Section 3 3 you need to combine loads for all higher level superelements at all levels For large superelement hierarchies with many loads this proce dure involves a large amount of input Load combination by the group method explained in Section 3 3 4 reduces the amount of input considerably compared to the one by one method explained in Section 3 3 2 but combinations must still be made for all superelements at all levels A more advanced method is offered by the LOAD ASSEMBLY command This involves making the load combinations directly for the top level superelement the complete mode
63. RPOSE Presel 01 OCT 2004 5 71 The command sets different parameters for controlling the DISPLAY PLOT and LABEL commands PARAMETERS ALTERNATIVE SCREEN DEVICE AUTO BASIC ELEMENT MODE CHARACTER TYPE SOFTWARE HARDWARE COLOUR BOUNDARY CONDITION ELEMENT LINES INCLUDED SUPERELEM NODE NUMBER NODE SYMBOL SUPER NODES colour tone DEVICE device name EYE DIRECTION This option is presently not in use This option has presently no function in Presel This option is presently not in use Choose how characters are displayed Device generated HARDWARE characters are faster but there may be restric tions on the character size and orientation Drawn characters are used this is the default choice Device generated characters are used Change the colour used for displaying a certain item Change the colour of boundary conditions default is medium blue Change the colour of element lines default is medium red Change the colour of superelement being included default is medium yellow Change the colour of node numbers default is medium green Change the colour of node symbols default is medium yellow Change the colour of supernodes default is medium blue Choose between the following colours WHITE GRAY BLACK BLUE GREEN ORANGE RED VIOLET and YELLOW Choose between LIGHT MEDIUM and DARK Choose the appropriate type of graphics device Type of graphics device WINDOWS is the def
64. TERS supno Number identification of a first level superelement SHOW PROGRESS This option causes feedback to be given on how many cards records are read The feedback looks like this 400 CARDS READ 800 CARDS READ etc By default no such feedback is given In previous versions of Presel such feedback was by default given SESAM Presel Program version 7 3 01 OCT 2004 5 67 ROTATE X AXIS ROTATE Y AXIS_ degrees Z AXIS PURPOSE The command rotates the display about the coordinate axes of the current superelement The SET GRAPHICS EYE DIRECTION and the interactive rotations provide alternative ways of rotating the display See the direct access buttons described in Section 3 1 about interactive rotation PARAMETERS X AXIS Rotate about the X axis Y AXIS Rotate about the Y axis Z AXIS Rotate about the Z axis degrees Angle in degrees Presel SESAM 5 68 01 OCT 2004 Program version 7 3 SET ANGLE TOLERANCE angtol COMMAND INPUT FILE comfilnam COORDINATE TOLERANCE cotol GRAPHICS JOURNALLING eens da a SET PRINT OFF NEW MODEL FILE prefix filnam orp PLOT PRINT UNIT VECTOR TOLERANCE _ uvtol PURPOSE The command sets different parameters for controlling the execution of other commands PARAMETERS ANGLE TOLERANCE angtol COMMAND INPUT FILE comfilnam COORDINATE TOLERANCE cotol GRAPHICS Specify the angle tol
65. a superelement is included several times a particular node will appear in several positions Therefore additional information is required to identify a specific node in the complete model A specific node in a superelement model is uniquely identified by so called node number triplets ij k where i is superelement number j is superelement index and k is node number Figure 3 5 includes a sketch of a model showing node number triplets for a couple of nodes 3 2 6 More About Nodes Nodes in a superelement hierarchy have the following characteristics e Nodes of a higher level superelement are the union of the supernodes of the included superelements e Nodes of a superelement not defined as super will not exist in a higher level assembly into which the superelement is included Therefore nodes not defined as super for the first level superelements in Prefem or Preframe will not exist as far as Presel is concerned e Nodes may be defined as super or given any other boundary condition only for the current higher level superelement e Nodes are identified by node number triplets superelement index node See Section 3 2 5 A node has as many triplets as there are first level superelements coupled to the node Any of these tri plets are unique identifications of the node e Any selection of the six degrees of freedom d o f of a node may be defined as super d o f the solid and membrane elements have only three d o f Note
66. am having knowledge about the existence of the wave loads Therefore when referring to a wave load in the load combination a warning is issued saying that the load case is accepted but it must be computed by a load program prior to performing the analysis The LOAD COMBINATION GROUP command is explained below referring to the model of Section 3 2 2 We assume that the model is subjected to wave loading from 8 directions and 12 frequencies altogether 96 global load cases As there are two occurrences of superelement 6 indexes 1 and 2 there will be a double set of loads computed by the wave loading program for superelement 6 This means that the L5 FEM file will contain 96 loads whereas the L6 FEM file will contain 192 loads Note There is a difference between Wajac and Wadam in the way they number the wave load cases when there are two or more occurrences of a superelement Their numbering systems are as follows in parentheses are given the numbering applicable to the current example In Wajac all wave loads for the first occurrence come first load cases 1 2 3 96 thereafter follows all wave loads for the second occurrence load cases 97 98 99 192 and so on See Figure 3 11 In Wadam the first wave load for all occurrences comes first load cases 1 and 2 thereafter follows the second wave load for all occurrences load cases 3 and 4 then the third wave load for all occurrences load cases 5 and 6 and so on See Figure 3 12
67. an system Alternatively you may give the boundary conditions in a pre defined cylindrical system defined by the COORDINATE SYSTEM com mand or with pre defined transformations a cartesian system with rotation compared to the global system defined by the TRANSFORMATION command This may for example be used to introduce a sloping slip surface rotate to a system having one of its axes normal to the slip surface and fix the translational d o f corresponding to this axis while letting the other two translational d o f s be free 3 6 Linear Dependency The LINEAR DEPENDENCY command offers two alternative types of linear dependency e General node dependency Two node dependency Using the general node dependency any d o f of a node may be made linearly dependent on any other d o f s of any other nodes The user explicitly specifies the linear dependency factor for all the independent d o f s The displacement of the dependent d o f will then be ra ra Bitra Botri Bat where r represents the displacements subscripts d and i represent the dependent and independent d o f s respectively and is the given dependency factors With the two node dependency all d o f s of a given node are made linearly dependent on the correspond ing d o f s of two other nodes The displacement of the dependent d o f s will be ra ra Prt 1 8 where 3 is a dependency factor given by the user Presel will compute a default value fo
68. and PARAMETERS select nodes Select nodes see Section 5 1 SESAM Presel Program version 7 3 01 OCT 2004 5 79 TASK ASSEMBLY SUB MODELLING TASK PURPOSE The command switches between the modes ASSEMBLY which is the normal way of using Presel as explained in this manual and SUB MODELLING which is for sub modelling as explained in the Submod User Manual As it is normally more convenient to access Submod directly rather than through Presel the TASK command has little relevance SESAM Program version 7 3 Presel 5 80 01 OCT 2004 TRANSFORMATION TRANSFORMATION trano spx spy spz gpx gpy gpz PURPOSE The command defines a rotated coordinate system A transformation matrix is established that transforms coordinates from a rotated coordinate system to the global coordinate system The purpose of the command 1S e For specifying a fixation or a prescribed displacement in a rotated transformed coordinate system See the BOUNDARY command e For specifying nodal loads in a rotated transformed coordinate system See the LOAD NODE com mand The transformation matrix is defined by giving the global coordinates of a second point SP and a guiding point GP The x axis of the transformed coordinate system Xr goes from the origin to SP The trans formed z axis Zr is perpendicular to Xy so that GP lies in the X Z y plane on the positive Zy side Yy is perpendicular to
69. and input file selected is Default and click OK This default Com mand input file reads the T FEM files located in the project area Optionally you may read the superelements 5 and 6 using the READ command SESAM Presel Program version 7 3 01 OCT 2004 3 7 free nodes are diamonds yellow on screen Com a Cad 4 i Ta 7 node numbers a ps LOL dl es e e oD E 4 a supernodes are circles ra 4 blue octagons on screen AX The two first level superelements 5 and 6 created by Prefem superelement 6 used here and here superelement 5 used here Desired complete model the top level superelement 7 Figure 3 3 The two first level superelements and desired complete model Figure 3 4 and Figure 3 5 take you step by step through the procedure and commands for assembling superelements 5 and 6 to form the complete model superelement 7 Presel SESAM 3 8 01 OCT 2004 Program version 7 3 Superelements as shown by DISPLAY commands Omit these if default Command input file is used There is nothing to display as ASSEMBLY NEW 7 the superelement is yet empty INCLUDE 5 NOPRINT CHECK INCLUDE PERFORM INCLUDE END DISPLAY CURRENT SUPERELEMENT LABEL NODE SYMBOL ALL The superelement being included is displayed with broken lines INCLUDE 6 DISPLAY TRANSLATE 0 3 0 DISPLAY NOPRINT CHECK INCLUDE L j PERFORM INCLUDE T Notice that nodes that END J were supernode
70. assembled into even higher level superelements all these triplets will appear in the table of matching nodes The typical appearance of the table will then be as shown in Figure 5 4 SUPER ELEMENT TYPE 31 LEVEL INCLUDE NODES BOU ASSEMBLY NODES SUP EL SUP EL EXT NOT SUP EL SUP EL EXT INDEX A lt B JODES MATCHING JODES NOT MATCHING Nodes of the Asterisk here Nodes of the Summary Coordinates in the superelement signals discrepancy of superelement information cartesian system of the being included boundary conditions assembly superelement assembly Figure 5 4 CHECK INCLUDE tabulates match between nodes here for higher level superelements The table header now informs that a superelement is being included in the third level superelement assem bly 31 The table contains the following information e The two first lines marked A says that the node 11 2 103 a triplet which is the same node as 11 3 101 and both belonging to the superelement being included matches node 12 1 703 of the superelement assembly The coordinates of these nodes are 20 20 0 The third and fourth lines marked B says that node 11 2 303 which is the same node as 11 3 303 and both belonging to the superelement being included matches node 12 1 803 which is the same node as 12 2 801 both belonging to the assembly The coordinates are 18 18 20 The asterisk signals that there is a discrepancy in boundary condition of the match
71. ault choice in a Microsoft Windows environment The command is currently of minor importance Set the viewpoint for the display Note that the default view point is set through command line arguments see Section 4 1 5 and these may in turn be set by Manager You can also use the ROTATE command or the interactive rotations using the direct access buttons described in Section 3 1 Presel 5 72 eyex eyey eyez HIDDEN INPUT NODE SELECTION PLOT FILE prefix filnam PRESENTATION COLOUR SUPERELEMENTS FILLED ELEMENT SCALING AUTOMATIC SHRINK FACTOR shrinkfac SIZE SYMBOLS BOUNDARY CONDITION SYMBOLS LOAD NUMBERS SESAM 01 OCT 2004 Program version 7 3 X Y and Z coordinates of the viewpoint the eye Switch hidden display mode ON and OFF The default is OFF Switch between graphical user interface ON and line mode OFF This command is currently irrelevant as the graphical user in terface is the only option for interactive execution of the pro gram Switch ON and OFF the possibility to select nodes graphically The nodes will be displayed as small dots yellow dots for free nodes and blue dots for supernodes The default is ON Set the name of the plot file By default it is the same as the model and command log files The extension of the plot file de pends on the plot format see the SET PLOT FORMAT com mand This command has the same functionality as the SET PLOT FILE command You may want
72. ay determine which load cases with what factor each included superelement contributes with to a given load combination This is available through the two commands DISPLAY LOAD FIRST CON TRIBUTING LOAD and DISPLAY LOAD NEXT CONTRIBUTING LOAD The FIRST CONTRIB UTING LOAD option colour codes superelements contributing with their load case number i where i is the lowest contributing load case number over all superelements Thereafter you should use the NEXT CONTRIBUTING LOAD option which colour codes superelements contributing with their load case number j where j is the second lowest contributing load case number Repeating the NEXT CONTRIBUTING LOAD option will loop through all contributing load cases The load factors are for each display printed on top of the colour coded superelements Note The loads values defined in Prefem Preframe and computed in Wajac Wadam cannot be dis played in Presel as it has no knowledge of the contents of these loads In addition to displaying the model the PRINT command is useful for verification purposes Various PRINT commands are exemplified in Figure 3 27 Figure 3 28 Figure 3 29 Figure 3 30 and Figure 3 31 SUPER EL TYPE LEVEL NODES ELEMENTS LOADCASES 1 1 295 304 3 2 1 826 857 1 3 1 319 310 0 10 2 110 3 3 100 3 29 2 3 This is the level of the superelement at For first level superelements this is number of basic elements for higher level superelements this is nu
73. being included Also see the PRINT T MATRIX sub command The table looks like this MIRROR ABOUT XY PLANE NO ROTATION ABOUT GLOBAL X AXIS 0 0000 ROTATION ABOUT GLOBAL Y AXIS 0 0000 ROTATION ABOUT GLOBAL Z AXIS 90 0000 TRANSLATION IN X DIRECTION 20 0000 TRANSLATION IN Y DIRECTION 0 0000 TRANSLATION IN Z DIRECTION 0 0000 NOTES The translations and rotations refer to the coordinate system of the superelement assembly Starting from the initial position of the superelement being included for example after RESET T MATRIX the translations and rotations must be made in the given sequence first mirror about the XY plane if rele vant then rotate about X etc in order to yield the position resulting from the accumulated transformations SESAM Program version 7 3 01 OCT 2004 DISPLAY The sub command displays the current position of the superelement being included on top of the superele ment assembly INCLUDE supno DISPLAY Presel PURPOSE 5 30 con g o 0 2 A oS PAR 3 Ss O w Oo O Ea a ae SANE H YAS et ere TP NS ar Y The superelement being included is incorrectly positioned superelement being included with broken yellow lines The superelement being included is correctly positioned Figure 5 5 DISPLAY sub command within the INCLUDE command SESAM Presel Program version 7 3 01 OCT 2004 5 31 INCLUDE supno DISTANCE CHECK NOD
74. between nodes See also Section 3 6 The dependency is defined by selecting a single d o f of a node to be dependent of any other d o f s of any other nodes You may keep defining several d o f s of a given node to be dependent And for each of these dependent d o f you may keep selecting independent governing nodes And finally for each of these independent nodes you may keep selecting d o f s to govern with a factor the displacement of the depend ent d o f Note Alternatively to defining the independent d o f as super prior to this command it may be made super within this command by the FORCE INTO SUPER option Using this option for a d o f that is already super has no consequence PARAMETERS dep node triplet Node number triplet supno index nodeno of the dependent node dep dof D o f to be dependent legal specifications are X Y and Z Translations in X Y and Z directions R X R Y and R Z Rotations about the X Y and Z directions indep node triplet Node number triplet supno index nodeno of an independent node indep dof The independent d o f legal specifications are X Y and Z Translations in X Y and Z directions R X R Y and R Z Rotations about the X Y and Z directions FORCE X INTO SUPER and similar for Y and Z FORCE R X INTO SUPER and similar for R Y and R Z If the independent d o f has not previously been defined as SUPERL or SUPER then use the appropriate of the FORCE INTO SUPER alternati
75. boundary condition must then have been defined only for the relevant d o f s Note that even if only selected d o f s have prescribed boundary condition values must be entered in the LOAD NODE command for all six d o f s The values given for the non prescribed d o f s are discarded The nodal loads may be verified by the PRINT LOAD command PARAMETERS Ic A single load case number to be defined for the current su perelement SESAM Program version 7 3 FORCE PRESCRIBED ACCELERATION PRESCRIBED DISPLACEMENT SELECT select nodes TAGGED UNTAGGED GLOBAL TRANSFORMATION trano fx fy fz mx my mz IMAGINARY COMPLEX ifx ify ifz imx imy imz PHASE COMPLEX pfx pfy pfz pmx pmy pmz END Presel 01 OCT 2004 5 55 The load is a force and or moment The load is a prescribed acceleration The load is a prescribed displacement Nodes are to be selected now Select nodes see Section 5 1 Refers to previously selected tagged nodes see the TAG UN TAG commands Refers to all but the previously selected tagged nodes see the TAG UNTAG commands The load is specified in the coordinate system of the superele ment The load is specified in a rotated coordinate system Transformation reference number previously defined by the TRANSFORMATION command Real components of the forces moments or prescribed dis placements accelerations The load is complex and the imaginary components are to be given Imaginary compon
76. des This may be done inside the BOUNDARY com mand by the SELECT option Or you may pre select the relevant nodes by the TAG command in which case you refer to these pre selected nodes by the TAGGED option inside the BOUNDARY command TAGGED is in effect a set with pre defined name you may also use the SET command to define sets In either case you need to select nodes using the node select features described in Section 5 1 As explained in Section 5 1 alternatively to selecting nodes directly by giving their triplets you may select a line plane or volume through or enclosing the desired nodes And these lines planes and volumes may be defined referring to nodes or to coordinates Moreover the coordinates may be given in the cartesian system or in a pre defined cylindrical system For example if you want to select all nodes in a plane you may find that the so called 2 PLANE option and giving two sets of cartesian coordinates is the quickest alternative First give a point in the plane and then a point defining together with the first point a normal to the plane All nodes on a cylindrical surface are easily Presel SESAM 3 36 01 OCT 2004 Program version 7 3 selected by the 2 PLANE option referring to a cylindrical system the first point is positioned in the desired cylindrical plane and the second point on a line through the first point and normal to the cylindrical axis By default the boundary conditions given refer to the global cartesi
77. displays superelements optionally with information about loads The nodes of the superele ment are shown by small coloured dots yellow for free nodes and blue for supernodes These node sym bols may be switched off and on again by SET GRAPHICS NODE SELECTION Node symbols node numbers and boundary conditions may be added by the LABEL command Note that there is also a DISPLAY command within the command sequence for including a superelement in an assembly The purposes of these two DISPLAY commands are different and should not be confused See the INCLUDE supno DISPLAY command PARAMETERS CURRENT SUPERELEMENT LOAD LOADED SUPERELEMENT glc FIRST CONTRIBUTING LOAD Display the current superelement The current superelement is set by the ASSEMBLY command Display the current superelement with information verifying the load combination The current superelement must be a higher level superelement Note that loads defined for first level superelements cannot be displayed or verified in Presel Colour code first level superelement occurrences according to how many local load cases each contributes with to the given global loadcase Global loadcase i e a load combination of the current higher level superelement This option is used in combination with the option NEXT CONTRIBUTING LOAD Combined the two options colour code first level superelement occurrences according to which loadcases they contribute with to a given g
78. e boundary conditions This may be fixations and or supernodes for coupling with other superelements Use the command BOUNDARY Presel SESAM 3 6 01 OCT 2004 Program version 7 3 d At this stage you may define load cases for the assembly This task may however also be postponed to after the complete model has been assembled See Section 3 3 on this 3 Create new second level superelements by repeating the process above item 2 4 Create new superelements at level three and higher levels by repeating the process above item 2 The only difference from creating second level superelements is that not only first level superelements are included Any mixture of first and higher level superelements may be included in the same new superele ment The level of the new superelement will be equal to the level of the highest level of the included superelements plus one 5 The assembly process is concluded when the top level superelement representing the complete model has been created Supernodes cannot be defined for the top level superelement 6 You should now define the loads for the various higher level superelements ref item 2 d above See Section 3 3 on this 3 2 2 Tutorial in Assembling Superelements The tutorial below illustrates how two first level superelements may be assembled to form a second level superelement Figure 3 3 shows the two first level superelements as well as the complete model For each first level superelement the dim
79. e table will be as shown below It is common practice to manually sketch the superelement hierarchy as shown in Figure 3 4 SUPER ELEMENT LEVEL 2 1 1 7 1 1 5 1 1 2 6 1 He 3 6 2 Figure 3 6 Sketch of superelement hierarchy Also see Section 3 8 on display and print commands for verifying the model 3 2 4 Identifying Superelement Occurrences Since a superelement may be included any number of times in a model each occurrence of the superelement is assigned a unique identification SESAM Presel Program version 7 3 01 OCT 2004 3 11 Within Presel there are two ways of uniquely identifying an occurrence of a superelement By referring to its superelement number plus superelement index The superelement index is the number in sequence in which the superelement was included see below for a more complete explanation In the LOAD COMBINATION command you need to refer to superelements in this way see Section 3 3 2 By referring to name and location string as used in the LOAD ASSEMBLY command see Section 3 4 Yet another way is employed in Sestra for determining selective retracking the SELID parameters on the RETR command in the Sestra input By referring to the string of hierarchy branch numbers from the top level superelement and down to the superelement in question The hierarchy branch numbers superelement numbers and superelement index
80. e the mesh on the plot Answer YES or No Include a symbol for the origin of the superelement coordinate system Answer YES or NO Include the boundary conditions on the plot Answer YES or NO Include node symbols on the plot Answer ALL NODES SUPER NODES ONLY or NONE Include node numbers on the plot Choose between COUPLED NODES NON COUPLED NODES EXTERNAL NODE NUMBER INTERNAL NODE NUMBER NODE NUMBER TRIPLET and NONE See explanations below Whether the AS LAST DISPLAY option is chosen or not the PLOT command is concluded by Enter four lines of text Each text line is limited to 24 characters and must be enclosed in apostrophes if containing blanks For example THIS IS A TEXT These lines are reproduced on the plot SESAM Program version 7 3 Presel 01 OCT 2004 5 59 e Finally the page size is given This is only relevant for the SESAM NEUTRAL plot format see the SET PLOT command For other plot formats give any parameter e g the default A4 The date and time is also reproduced on the plot together with scale superelement number and the superele ment level The scale is based on the assumption that metres are used as unit for the coordinates PARAMETERS AS LAST DISPLAY text page size ALL NODES SUPER NODES ONLY COUPLED NODES NON COUPLED NODES EXTERNAL NODE NUMBER supno index INTERNAL NODE NUMBER NODE NUMBER TRIPLET ONE NODE NUMBER TRIPLET ALL NODE NUMBER TRIPLETS The screen d
81. el SESAM 4 8 01 OCT 2004 Program version 7 3 SESAM Presel Program version 7 3 01 OCT 2004 5 1 5 COMMAND DESCRIPTION The hierarchical structure of the commands and numerical data is documented in this chapter by use of tables How to interpret these tables is explained below Examples are used to illustrate how the command structure may diverge into multiple choices and converge to a single choice In the example below command A is followed by either of the commands B and C Thereafter command D is given Legal alternatives are therefore AB D and A C D B A D C In the example below command A is followed by three selections of either of commands B and C as indi cated by 3 For example A B B B or A B BC or A C BC etc B A 3 C In the example below the three dots in the left most column indicate that the command sequence is a contin uation of a preceding command sequence The single asterisk indicate that B and C may be given any number of times Conclude this sequence by the command END The three dots in the right most column indicate that the command sequence is to be continued by another command sequence B A C END In the example below command A is followed by any number of repetitions of either of the sequences B D and C D Note that a pair of braces is used here merely to define a sequence that may be repeated The braces are not co
82. ement 10 the location strings A and B Thereafter we may choose to merely append a character to the location strings each time superelement 10 is repeated by repeating higher level superelements We will end up with location strings as shown However this may not be a very logical convention for location strings First level superelement 10 is given name TRIANGLE N W E 10 Second level superelement 20 includes 10 twice first level 1 0 with no translation rotation secondly with 180 rota S tion Location strings are assigned by LOCATION CREATE A for shaded area LOCATION CREATE B for blank area location 2 strings re level 2 Third level superelement 30 includes 20 twice second inclusion is mirrored about a vertical south north plane Location strings are modified by LOCATION USE C for shaded area LOCATION USE D for blank area Fourth level superelement 40 includes 30 twice second inclusion is mirrored about a vertical west east plane First level superelement 10 is also included directly Location strings are modified and created by LOCATION USE E for shaded area LOCATION USE F for blank area LOCATION CREATE G for hatched area Figure 3 22 Location string convention alternative 1 Presel SESAM 3 34 01 OCT 2004 Program version 7 3 Alternatively we may want location strings reflecting the positions of the superelement occurrences relative to the north west south and east directions EN means ea
83. eness ASSEMBLY NEW 10 NAME CREATE STOREY When including superelements 2 long wall and 3 short wall twice each and superelement 4 floor these are assigned location strings The LOCATION CREATE command is used INCLUDE 2 NOPRINT CHECK INCLUDE LOCATION CREATE SOUTH PERFORM INCLUDE o 3 NOPRINT CHECK INCLUD LOCATION CREATE SOUT PERFORM INCLUDE HL FI oo RANSLATE 0 4 0 PRINT CHECK INCLUD CATION CREATE NORT ERFORM INCLUDE O m m EZRA O Gl ole RANSLATE PRINT CHECK INCLUD OCATION CREATE NORT ERFORM INCLUDE 0 0 w e om FI A 2H O CJ ole RANSLATE PRINT CHECK INCLUDE CATION CREATE BASIC ERFORM INCLUDE 0 0 8 Dio Q O we 2H O END Figure 3 18 shows the current identifications of the superelement occurrences included in superelement 10 STOREY The short and long walls are given location strings corresponding to their southerly and northerly positions The four wall superelements now have unique identifications in terms of names plus location strings The floor is given the location string BASIC it is neither southerly nor northerly Note The LOAD ASSEMBLY command can only refer to superelement occurrences having loca tion strings Even a superelement not repeated and therefore having a unique name must be given a location string The location s
84. ensions the origin the free internal nodes and the supernodes are given As can be seen superelement 5 is used once and superelement 6 is used twice to form the complete model If you only want to read this section i e you do not intend to perform the tutorial then you may skip the four item list of required actions below If you want to perform the tutorial and run Presel for this example you first need to do the following e Start the SESAM Manager and open a new project When doing so click Structure Type and choose General You may also select type of structure after opening the new project by Options Structure Type e In Manager click Options Superelement and within the window appearing set your analysis to be Superelement analysis as opposed to Direct analysis and set Top level superelement number to 7 e Create the two first level superelements 5 and 6 by running Prefem twice Remember to set the superele ment number before starting Prefem The input for the two superelements is provided in Appendix A TUTORIAL EXAMPLES Section A 1 Rather than clicking typing the commands you may want to cre ate two command input files using an editor Note that node numbers in a FE model are automatically generated by Prefem and may with a new program version deviate from the numbers shown in Figure 3 3 e Start Presel as follows Click Model Superelement Handling Presel to open the Superelement han dling window Make sure the Comm
85. ent superelement is the one e Displayed when issuing the DISPLAY CURRENT SUPERELEMENT command For which boundary conditions are given when issuing the BOUNDARY command e Into which superelements are included when issuing the INCLUDE command e For which load combinations are given when issuing the LOAD command Ete PARAMETERS supno The superelement number A vacant superelement number for the NEW option an existing one for the OLD option SESAM Presel Program version 7 3 01 OCT 2004 5 9 BOUNDARY FREE GLOBAL FIXED LOCAL COORDINATE SYSTEM coord name BOUNDARY PRESCRIBED 6 SUPER TRANSFORMATION trano fixcode SELECT select nodes TAGGED UNTAGGED END PURPOSE The command defines boundary conditions for the current superelement which must be a higher level superelement i e boundary conditions cannot be defined within Presel for first level superelements The following boundary conditions may be defined for each individual degree of freedom d o f of the nodes FREE Free to move FIXED Fixed at zero displacement PRESCRIBED _ Prescribed displacement or acceleration value is given by the LOAD command SUPER Superdof In addition the boundary conditions LINEAR and SUPERL are defined using the LINEAR DEPEND ENCY command SUPERL has exactly the same effect as SUPER only that it was defi
86. ents created by SESAM s preprocessor for tubular joint modelling Pretube may also be assembled by Presel The same goes for superelements created by any FE preprocessor as long as they are defined according to the SESAM Input Interface File format To fully appreciate the purpose and use of Presel an understanding of the mathematical foundation of the superelement technique is required see Appendix B THEORY Also a basic understanding of a first level superelement as modelled by e g Preframe and Prefem is required Presel 1 2 Example 1 Quarter model of a tank This example illustrates how part models may be assembled to form the complete model a quarter of a cylindrical tank with flat bottom and spherical top The part models are Superelement 11 a quarter of a dome Superelement 12 a quarter of a cylinder Superelement 13 a quarter of a circular plate superelement 11 01 OCT 2004 superelement 21 SESAM Program version 7 3 Superelements 11 12 and 13 are first level superelements They are assembled into a second level superelement assembly superelement 21 the complete model to be analysed The complete model is often referred to as the top level superelement superelement 13 Example 2 Full model of a tank The whole tank may be modelled by including superelement 21 four times and rotating it 0 90 180 and 270 to form a third level superelement 31 The hierarc
87. ents of the forces moments or prescribed displacements accelerations Prescribed rotations are given in radians The load is complex and the phase angle components are to be given Phase angle components in degrees of the forces moments or prescribed displacements accelerations Give END rather IMAGINARY COMPLEX or PHASE COM PLEX to conclude the command and make the load non com plex Presel SESAM 5 56 01 OCT 2004 Program version 7 3 NAME NAME CREATE name PURPOSE The command creates a name for a superelement It is used in connection with the LOAD ASSEMBLY command See Section 3 4 for an explanation of assembling loads PARAMETERS name Name given to the current first or higher level superelement It is a string of maxi mum 8 characters SESAM Presel Program version 7 3 01 OCT 2004 5 57 OPTIMIZE BANDWIDTH OPTIMIZE supno OPTIONS PROFILE PURPOSE The command optimises rearranges the internal node numbering of a higher level superelement The objective of this is to reduce the bandwidth or profile of the stiffness matrix of the superelement thereby reducing the time required to solve the equation system of the superelement this is done in the analysis pro gram e g Sestra Note The node numbers seen by the user the node number triplets are not affected by this opera tion The superelement cannot be a first level superelement First level superelements must be
88. ents then a wild card reference in the LOAD ASSEMBLY command matching the higher level superelements will pick up loads from this superelement directly in addition to loads picked up from first level Therefore LOCATION CREATE is not used when including 10 STOREY in the HOUSE below or else the wild card when defining load 1 gravity see Section 3 4 3 will pick up gravity loads from 10 in addition to gravity loads directly from first level Gravity for parts of the model will erroneously contrib ute twice Figure 3 19 illustrates the final identifications of the superelement occurrences of superelement 100 HOUSE SESAM Presel Program version 7 3 01 OCT 2004 3 29 ROOF BASIC N a x _ SWALL NORTHIST S _ LWALL SOUTHIST LWALL NORTHIST P FLOOR BASICIST SWALL SOUTHIST SWALL NORTHGRD LWALL SOUTHGRD LWALL NORTHGRD SWALL SOUTHGRD EFNDT BASIC third level superelement 100 the complete model name is HOUSE FLOOR BASICGRD Figure 3 19 Identifications of superelement occurrences within superelement 100 HOUSE Now the assembling of superelements including assigning of occurrence identifications is complete Their identifications have become more specific in parallel with knowing more about their final positions Figure 3 20 shows the superelement hierarchy with superelement numbers indexes names and location strings SESAM Program version 7 3 Presel 3 30
89. er if a superele ment is rotated as is the case for the second inclusion of superelement 6 in the example of Section 3 2 2 then the reduced matrices must be transformed before being added to the stiffness and load matrices of the superelement assembly When translating rotating and mirroring a superelement to include it in a superelement assembly a transfor mation matrix is established see the INCLUDE supno PRINT T MATRIX command The three by three cosine matrix part of this three by four transformation matrix constitute the required transformation for the reduced matrices If T is the name of this three by three cosine matrix the d o f vector of the reduced superelement after the transformation is rp Tr B 16 The stiffness and load matrices are transformed as follows note that for the orthogonal three by three trans formation matrix T the inverse matrix is equal to the transformed matrix k T kT B 17 F TF B 18 It follows from the last equation that the loads of a superelement are rotated and mirrored along with the superelement when this is being included in a superelement assembly Translations of the superelement has no effect on the loads This is exemplified in Section 3 3 2 where load 3 on superelement 6 see Figure 3 8 is rotated and multi plied by 2 when combined into global load 2 of top level superelement 7 see note 6 of Figure 3 9 Also note that to allow the stiffness k and load F matrices t
90. erance used for determining whether an angle is 90 degrees or not The angle tolerance in degrees the default value is 0 001 Specify a command input file The file is opened and is ready for reading using the command The command input file can not have the same name as the Presel command log file Note that specifying and reading a command input file is nor mally more conveniently done through Manager Name of the command input file The file extension must be JNL and shall not be given Specify the coordinate tolerance used for deciding whether two points nodes have the same geometrical position and for de ciding whether a node lies in a plane or on a line The coordinate tolerance given in the same unit as the coordi nates The default value is 0 1 Set various parameters controlling the display and plot The command is described in detail in the following SESAM Program version 7 3 JOURNALLING MODEL FILE prefix filnam NEW OLD PLOT PRINT UNIT VECTOR TOLERANCE uvtol Presel 01 OCT 2004 5 69 Switch on or off journalling of the selected set of commands i e either GRAPHICS or PRINT commands Journalling is off when the program is started even if journalling was switched on in a previous session with the same model file Close the current model file and open another without exiting and re entering the program When accessing Presel through Manager you should not use this command The prefix
91. erelement loads Refers to superelement occurrences refname is the name of the lower level su perelement refloc is the location string of the superelement occurrence refname and refloc are given as indicated separated by a punctuation mark only The aster isk may be used as wild card In the following examples the characters A B X and Y should be interpreted as any number of characters names and location strings are both limited to 8 charac ters are all lower level superelements and all location strings of these I e absolutely all superelement occurrences at any level for which names and location strings have been defined A X are all lower level superelements with names ending with A and all location strings of these ending with X A X are all lower level superelements with names beginning with A and all lo cation strings of these beginning with X A B X Y are all lower level superelements with names beginning with A and containing B and all location strings of these containing X and ending with Y Local load case number of the lower level superelements being referred to Factor to apply to the local load case Presel SESAM 5 52 01 OCT 2004 Program version 7 3 LOAD COMBINATION COMBINATION Mc factor supno index gle END END supno index STEP lowllc incr factor END GROUP lowgle higlc step
92. ers has to be enclosed within single quotes this is a text e percentage sign at the beginning of a line is used for entering a comment Comments will be logged together with commands on the command log file see Section 4 1 3 Note that the program will occasionally log information on the command log file this will appear as comments in between data and comments entered by the user The program information is preceded by two percentage signs to distinguish it from the user s own comments This makes it easy to strip a command log file for program information in connection with creating a command input file any fairly good editor will have a macro functionality or similar enabling you to locate and remove all lines with Moreover comments preceded by will not be logged on the command log file to avoid irrelevant logging of program information when using an unedited command log file as a command input file SESAM Presel Program version 7 3 01 OCT 2004 4 3 4 1 3 Files used by Presel The file environment of Presel is illustrated in Figure 4 1 The file extensions MOD JNL etc are given together with file descriptions Command Interactively input file given JNL user input first level higher level Plot file varies Command log file journal JNL Model file data base MOD mre MOP NAMA Z JCW Z Print file LIS
93. es are all given in the superelement hierarchy printed by Presel as shown in Section 3 2 3 Each superelement is identified by three numbers Branch number within the superelement assembly Superelement number e Superelement index The first time a superelement number is included in an assembly it is assigned index 1 The second time it is included it is given index 2 and so on When a higher level superelement is repeatedly included in an assembly the indexes of its included superelements will also be incremented If for instance the second level superelement 7 in the current example were to be included twice in a third level superelement 9 then a superelement 5 with index 2 would appear also two new occurrences of superelement 6 would appear namely indexes 3 and 4 this is illustrated in Figure 3 7 SUPER ELEMENT LEVEL level number a 3 2 1 1 9 1 1 7 1 1 5 1 2 6 1 3 6 2 2 7 2 1 5 2 branch number E Ss 226 3 superelement number superelement index oe 3 6 4 Presel s table Manual sketch Figure 3 7 Superelement hierarchy second level superelement 7 included twice in third level 9 Presel SESAM 3 12 01 OCT 2004 Program version 7 3 3 2 5 Identifying Nodes in a Superelement Model In a superelement model it is easily recognised that the node number itself is not enough information to uniquely identify a node In particular when
94. esttsesestestsstsessssesesseseeees 5 37 INCLUDE supno POSITION ceeceeceseesesseeeecesceaecacesceeceeseeseceaesaeeaeeaeeeceaeeaecaeeeeeeneeaecaecaeeaeeaees 5 38 INCLUDE supno PRINT T MATRIX PRINT INV T MATRIX 0 cecccscceteeeteeeeeeeeeeteeeteeeneens 5 39 INCLUDE supno RESET T MATRIX oo eceeceeccescceccnceesceseesececesaesaeeseseeceaecaecaeseneeeeeaecaaeaeeneeeeeees 5 40 INCLUDE Supno ROTATE ccoo loan dobsateviak a eE E 5 41 INCLUDE supno TRANSLATE 000 pas 5 43 LABEL id AA esas pe ells ees E EE EE 5 44 LINEAR DEPENDENCY ini idad 5 46 LINEAR DEPENDENCY GENERAL NODE DEPENDENCY coococccccoccoconnnconnnnonnnnnnnonnnnoranennnnos 5 48 LINEAR DEPENDENCY TWO NODE DEPENDENCY oncoccncoccnoonnonnncconnnnonnnconnnnnnn nono nocnncnnnos 5 49 BAD O e At tees leaees 5 50 EDAD ASS EMBED UD cd resets DA oO eatin nts izes eaS 5 51 EOAD COMBINA ON sto ta ae aaee aii la iia 5 52 EOAD NODE tro eee E o a e soles 5 54 NAM o a e tae 5 56 OPTIMIZE 200 dt 5 57 PEO Di Ad 5 58 PRINTS a e au US Be ELT a wht ve 5 60 PRINTLOAD a A S E E E 5 62 PRINT NODE cad T EE cates deen of ae eons E ER per astern es 5 64 READ A A ne Sh a Seas eaa a e a a a a 5 66 ROTATE herh aeir A o a raaa a AS 5 67 S D EE A EA E ETT A AEEA AE ATEA ETT 5 68 SEO GRAPHIC E AAEE EEE E AEE E EE A T 5 70 SI A M d E OA BAROT E A EEA TA AE EE ATE 5 74 SET H INE DEEE EEE ENRETE EEN ETE 5 76 DIA E A E AE A A T EEE O NT 5 78 TAS A A A A REEE 5 79 TRANSFORMATION aea se EEEE T eE e eE E 5 80 UNTA Gs 5
95. face File and writes STRUCTURAL higher level superelements to the same ANALYSIS Figure 2 1 Interface between SESAM preprocessors and analysis programs Presel produces Input Interface Files for all higher level superelements by the command WRITE WRITE top where top is the number of the top level superelement All higher level superelements are implicitly and automatically written when this command is given Note that when the SESAM Manager is employed the writing of the top and higher level superelements is normally controlled by Manager thus making the WRITE command superfluous Note If you on MS Windows close the Presel window by the X in the upper right corner or by the Close Alt F4 command of the window menu then the Input Interface Files will not be writ ten even though you have requested this when starting Presel This feature may be used if you change your mind and decide not to write the file after having started Presel SESAM Presel Program version 7 3 01 OCT 2004 3 1 3 USER S GUIDE TO PRESEL The purpose of Presel is to assemble put together part models so called first level superelements to form the complete analysis model This is done through the following steps Read files of first level superelements this is normally done automatically e Create a second level superelement assembly and include first level superelements into it The inclusion process comprises positioning the first
96. fined Table 5 1 describes these rules for the dependent d o f and Table 5 2 for the independent d o f A violation of the rules involves that the linear dependency is not accepted Table 5 1 Rules for boundary condition of a dependent d o f Boundary cond before Boundary cond after Comment FREE LINEAR OK FIXED LINEAR Warning the boundary condition is changed PRESC Illegal a prescribed cannot be made dependent LINEAR LINEAR OK implies adding dependency of new d o f s SUPER LINEAR Warning the boundary condition is changed SUPERL Illegal linear dependency cannot propagate Table 5 2 Rules for boundary condition of an independent d o f Boundary cond before Boundary cond after Comment FREE SUPERL OK if FORCE INTO SUPER is used FIXED SUPERL OK if FORCE INTO SUPER is used PRESC Illegal cannot be changed to super LINEAR Illegal d o f is not independent SESAM Presel Program version 7 3 01 OCT 2004 5 47 Table 5 2 Rules for boundary condition of an independent d o f SUPER SUPERL OK SUPERL SUPERL OK Presel SESAM 5 48 01 OCT 2004 Program version 7 3 LINEAR DEPENDENCY GENERAL NODE DEPENDENCY GENERAL NODE DEPENDENCY dep node triplet as dep dof indep node triplet indep dof beta PURPOSE The command defines general linear dependency
97. fixT FEM where e prefix is an optional character string that may and may not include a directory specification the string is given when entering Presel and is common for all superelements in the model e T is a mandatory character identifying this as an Input Interface File a T file as opposed to a Loads Interface File L file which uses character L and a Results Interface File R file which uses character R e is the superelement number the identifier of the superelement Presel SESAM 2 4 01 OCT 2004 Program version 7 3 e FEM is a mandatory file extension Normally the user may find it convenient to leave the prefix void This is also the default condition An example of a name of an Input Interface File with prefix is ABCTS FEM Note that Presel both reads first level superelements and writes higher level superelements and all must have the same prefix If the above file superelement 5 is one of several files of a superelement model then all Input Interface Files should be named ABCT FEM where is the superelement number PRE PROCESSING ENVIRONMENTAL Prefem ANALYSIS Legend for arrows 1 first level superelement 2 second and higher level superelement general As indicated by the illustration LOADS INTERFACE FILE Prefem and Preframe write first level superelements to the Input Interface File Presel reads first level superelements from the Input Inter
98. have 8 wave load cases computed by Wadam As both 11 and 12 are used twice Wadam will compute 16 loads for each superelement When combining loads for superelement 21 we must therefore create 16 load combinations Using the LOAD COMBINATION GROUP command the input will be lowglc higlc step sup indx lowllc factor LOAD COMB GROUP 1 16 1 11 1 1 1 0 12 1 L 1 0 END END END The load combination for superelement 31 will be lowglc higlc step sup indx lowllc incr factor LOAD COMB GROUP dl 8 1 21 1 STEP 1 2 1 0 21 2 STEP 2 2 1 0 END END END 3 3 6 Requirement to Assembling Process when Wave Loads are Computed Note Wajac and Wadam are based on the assumption that for all superelements the indexes are numbered consecutively 1 2 3 when counting the individual superelements numbers from top to bottom in the table printed by Presel It is possible to assemble the superelements in such a way that the combination of wave loads computed by Wajac and Wadam will fail A description follows below of 1 an awkward superelement hierarchy 2 a hierarchy that fails in combination with Wajac and Wadam and 3 a proper hierarchy Presel SESAM 3 22 01 OCT 2004 Program version 7 3 1 Awkward Superelement Hierarchy Consider the example of Figure 3 14 Superelement 11 is included in superelement 31 prior to superelement 21 i e 11 is found in branch 1 while 21 is found in branches 2 and 3 Superelement 21 a
99. he location strings of several first level superelements to be modified by a single LOCATION USE command by appending characters to the strings You need to determine a convention for location strings for your model You also have to device a scheme for how to arrive at this convention i e how to employ the LOCATION CREATE and LOCATION USE commands during the assembly process The scheme will depend on how the superelement hierarchy is organised To be able to determine a practical convention and a scheme you should be familiar with the pos sibilities and limitations of the LOCATION USE command see Chapter 5 for this You may find that assigning name and location strings to your superelement occurrences will influence the organisation of the superelement hierarchy In the house example of Section 3 4 2 and Section 3 4 3 we were able to merely append characters to the location strings assigned the first time For example when the long wall LWALL was included in the second level superelement STOREY the first time it was assigned location string SOUTH Later in the assembly process the location string was merely appended by GRD and 1ST because these occurrences were all located in a southerly direction This may not always be possible Consider the example of Figure 3 22 A single superelement 10 is used nine times to establish the complete model 40 at fourth level When being included into the second level superelement 20 we may decide to give superel
100. hical structure of the superelement model is shown Figure 1 1 Illustration of superelement hierarchies SESAM Presel Program version 7 3 01 OCT 2004 1 3 1 2 Presel in the SESAM System SESAM is comprised of preprocessors environmental analysis programs structural analysis programs and postprocessors An overview of SESAM is shown in Figure 1 2 ENVIRONMENTAL ANALYSIS PREPROCESSING POSTPROCESSING va Paa Z A fee 3 ES ASSOCIATED INTEGRATED Figure 1 2 SESAM overview Presel SESAM 1 4 01 OCT 2004 Program version 7 3 1 3 How to read the Manual If you are a new user then first read the introduction in Section 1 1 Continue with Section 2 1 and skim through Section 2 2 to learn about basic features and principles of assembling superelements If you already have a basic understanding of SESAM and the superelement technique then proceed as fol lows e Read Section 3 1 to learn how to start Presel and use the graphical user interface e Read Section 3 2 1 to learn about the basic procedure of assembling superelements Study the tutorial in assembling superelements of Section 3 2 2 e Read Section 3 2 3 Section 3 2 4 and Section 3 2 5 to learn how to identify superelements and nodes Note two important rules mentioned in Section 3 2 6 e Read Section 3 3 1 and study the tutorial in combining loads in Section 3 3 2 e Conclude by looking into Section 3 3 3 Section 3 5 Sectio
101. hrough intermediate combinations contributes to a top level load combination has no effect 3 3 2 Tutorial in Combining Loads One by One This tutorial is based on the same example as the tutorial in assembling superelements Section 3 2 2 You should do the tutorial in assembling superelements first You should also read Section 3 3 and Section 3 3 1 The loads for the example of Section 3 2 2 are shown in Figure 3 8 Both the local loads for the two first level superelements loads defined in e g Prefem and the desired global loads for the complete model are shown Presel SESAM 3 14 01 OCT 2004 Program version 7 3 As you will see this tutorial does not have loads numbered from 1 and up This will result in zero loads fill ing in the gaps in the load numbering thereby consuming some additional computational time and disk space This is therefore in conflict with normal and advisable practice The reason for numbering the loads like this is merely to avoid confusion in the tutorial between loads superelement numbers and superelement indexes Note Number the load cases and combinations from 1 and up to avoid zero load cases which would result in waste of computational time and disk space 1 5 gle superelement 5 index llc 8 Desired two global loads glc Local loads llc for the first level superelements 5 and 6 for the top level superelement 7 Figure 3 8 Loads modelled for the first level superelements and desired loads
102. iK K r R K K R B 8 or kr F B 9 where O Paci k Ky KK K B 10 Til F R K K R B 11 When this operation is performed for both superelements A and B their matrices are reduced as follows K gt k r4 gt Tis R gt F K gt Kpg rg gt Fa R gt Fp When superelements A and B are coupled it follows that Pas Vp Fs B 12 What this means is that both superelements A and B contribute with stiffness and loads to the supernodes The reduced stiffness and loads may consequently be added k k r F Fj B 13 This is the equation of equilibrium for the complete model expressed in the d o f s of the top level superele ment Solving this equation yields r When r is known the internal displacements of A and B r4 and rp respectively are found by inserting r in Equation B 7 the matrices of this equation are saved during reduction of each superelement This operation is termed retracking 1 1 Ky Kg Ko rs FK Raj B 14 p xj e B 15 rg Kg K gists Kg Ro Presel SESAM APPENDIX B 4 01 OCT 2004 Program version 7 3 The terms reduction solving and retracking are highlighted above as these are three major phases of a superelement analysis sequential processes automatically executed by the analysis program Sestra B13 Rotating and Mirroring a Superelement In the example of Section B 1 2 none of the superelements are rotated or mirrored Howev
103. ing pair of nodes marked B This means that the superelement cannot be included in the assembly See Section 3 2 6 about requirements to nodes The summary at the bottom says that the assembly has 12 nodes not matched by any nodes of the superelement being included 2 pairs of nodes match 0 nodes of the superelement being included does not match any of the assembly nodes all match and the total number of nodes in the assembly counting the ones of the superelement being included is 14 NOTES CHECK INCLUDE or NOPRINT CHECK INCLUDE is mandatory and must be given before PERFORM INCLUDE Presel SESAM 5 28 01 OCT 2004 Program version 7 3 The DISTANCE CHECK sub command can be used to find the distance between the two nodes If this dis tance is greater than the coordinate tolerance printed in the heading of the tables the nodes will not match Assuming that the superelement being included has been positioned correctly there are only two ways to get non matching nodes to match you must either correct the first level superelements leave Presel and re run after the correction or increase the coordinate tolerance see the SET COORDINATE TOLERANCE com mand SESAM Presel Program version 7 3 01 OCT 2004 5 29 INCLUDE supno DECODE T MATRIX DECODE T MATRIX PURPOSE The sub command prints the transformation matrix containing the accumulated translations rotations and mirrorings of the superelement
104. is used for Wadam and not for Wajac The LOAD COMBINATION GROUP command must be given for each higher level superelement Still the amount of input is manageable Note There is a requirement to the way the superelements are assembled to get a proper numbering of the wave loads computed by Wajac and Wadam Section 3 3 6 explains this 3 3 5 Load Combinations when Higher Level Superelements are Repeated Figure 3 13 shows a superelement hierarchy in which superelements 11 and 12 are included in a superele ment 21 And superelement 21 is included twice in superelement 31 As seen in the table printed by Presel superelement 11 appears in the final assembly with indexes 1 and 2 Index 2 comes into being when SESAM Presel Program version 7 3 01 OCT 2004 3 21 superelement 21 is included in 31 the second time Superelement 12 also appears with indexes 1 and 2 for the same reason 1 31 1 1 21 1 wia y i 2 L 22 12 L 21 ieee SA i mone ACA a 1 2 1 2 l 2 12 2 ha fa aj 1 Presel s table Manual sketch Figure 3 13 Superelement hierarchy with repeated higher level superelement In the load combination however there will only be references to index 1 for superelements 11 and 12 This is because the higher level superelement 21 only recognises index 1 of superelements 11 and 12 It doesn t know that itself is going to be included twice in superelement 31 Let us assume that we
105. isplay with current labelling and other display in formation is plotted The screen display with current labelling and other display in formation is plotted The page size Choose between Al A2 A3 A4 and AS A4 is the default choice All node symbols are shown Only supernode symbols are shown Add numbers to the plot telling how many first level superele ments there are coupled to each node The numbers are only given for nodes where to or more first level superelements are coupled i e the number will always be gt 2 Also see the NON COUPLED NODES alternative Add the number 1 to the plot for all nodes to which only a single first level superelement is coupled There will be no label for nodes where two or more first level superelements are coupled This alternative is the complement to COUPLED NODES Add only the node number of a given first level superelement Superelement number and index of a first level superelement Add only the internal number of the current superelement as sembly normally this is of little interest to the user Add one or all node number triplets the full and unique ref erences to nodes see Section 3 2 5 about triplets Only one of possibly several triplets is shown The program au tomatically selects which of the triplets to show All triplets are shown reflecting the fact that the nodes have one triplet for each first level superelement connected
106. l regardless of how many intermediate superelement levels there are Presel SESAM 3 24 01 OCT 2004 Program version 7 3 To be able to use the LOAD ASSEMBLY command unique identifications must be given for all occur rences of first level superelements for which loads exist Giving such unique identifications makes the task of assembling the superelements more complex But as shown by the example below defining the loads requires considerably less input There is another advantage of the load assembly method The LOAD ASSEMBLY command will not be affected by changes to the superelement hierarchy This is because the principle of this method is to give identifications for superelement occurrences depending on their final location in the complete model The order in which the superelements are assembled is of no consequence 3 4 1 Principles of Uniquely Identifying Superelement Occurrences When a superelement is created by Prefem or Preframe it can be viewed as a building brick with no specific location in the complete model The same can be said about any higher level superelement created in Presel Only when the top level superelement is created then all lower level superelement occurrences including the first level superelement occurrences will have determined locations Note the terminology e Superelement is a building brick with no specific location e Superelement occurrence represents an actual part of a higher level superelement
107. le contains graphic information produced by the PLOT command The file extension will depend on the plot format chosen see the SET PLOT FORMAT command See Section 4 1 4 for advice on using the CGM format to include plots in reports The Input Interface File FEM termed T files for short is comprised of First level superelements created by Prefem or Preframe which are read by Presel and Higher level superelements which are written by Presel Presel has been designed to protect the user against loss of valuable data However accidental loss of data may occur This may be caused by the user by for example inadvertently deleting the model file or it may be due to an inconsistency in the data model Such inconsistency may occur for several reasons The computer goes down e The disk is full the disk quota is exhausted or user privileges are inadequate There is an error in the program If Presel discovers an inconsistency in the data model the program will normally close all files opened and abort the execution Presel may then be restarted using the model file In some cases however it will not be possible to resume normal execution due to an irrecoverable inconsistency If the model file is lost it can be reconstructed by re executing the program and reading input from the command log file i e using it as a command input file Note The model file will normally not be co
108. ling superelements in an assembly and only want to make a quick check of the appearance of a certain superelement Furthermore the DISPLAY LOCATE SUPERELEMENT command allows highlighting by a different col our a given first level superelement in an assembly Note There are shortcut command buttons under the headings DispMod and Display for all dis play alternatives explained above Figure 3 26 Display of a superelement using the hidden option The LABEL command may be used to add information to the displayed superelement You may also use the DISPLAY option during the inclusion of a superelement to see the current position of the superelement being included 1 e to check its position before you complete the inclusion The tutorial of Section 3 2 2 illustrates this and the description of the INCLUDE supno DISPLAY command in Chapter 5 shows an example This display cannot be annotated by the LABEL command You may also verify the load combinations for an assembly using the DISPLAY LOAD command There are two ways of doing this SESAM Presel Program version 7 3 01 OCT 2004 3 39 e You may determine how many load cases each included superelement contributes with to a given load combination This is available through the DISPLAY LOAD LOADED SUPERELEMENT command Colour coding of the superelements indicates which of them contribute with no load cases which con tribute with one which contribute with two and so on e You m
109. load types This command differs from the command defining the load in that a load index must be given The load index is used to distinguish between individual loads of the same type for the same node for the same load case For example a nodal force defined for the second time for the same node for the same load case is given index 2 Note that load indexes may change after deleting a load as the index always goes from 1 to N where N is the number of loads of the same type for that particular node PARAMETERS lc ALL YES NO SELECT select nodes TAGGED UNTAGGED FORCE Load case number Delete all loads Confirm deletion Nodes are to be selected now Select nodes see Section 5 1 Refers to previously selected tagged nodes see the TAG UN TAG commands Refers to all but the previously selected tagged nodes see the TAG UNTAG commands Delete nodal force loads Presel SESAM 5 20 01 OCT 2004 Program version 7 3 PRESCRIBED ACCELERATION Delete nodal acceleration loads PRESCRIBED DISPLACEMENT Delete nodal displacement loads index Load index either select one index or all by entering the text ALL SESAM Presel Program version 7 3 01 OCT 2004 5 21 DISPLAY CURRENT SUPERELEMENT LOADED SUPERELEMENT glc FIRST CONTRIBUTING LOAD glc LOAD DISPLAY NEXT CONTRIBUTING LOAD END LOCATE SUPERELEMENT supno SPECIFIED SUPERELEMENT supno PURPOSE The command
110. lobal loadcase FIRST CONTRIBUTING LOAD displays with a separate col our the first level superelements that contribute with their load Presel 5 22 NEXT CONTRIBUTING LOAD LOCATE SUPERELEMENT supno SPECIFIED SUPERELEMENT SESAM 01 OCT 2004 Program version 7 3 case 1 If no superelements contribute with their loadcase 1 then the lowest contributing loadcase when accounting for all first level superelements is shown instead Thereafter repetitive use of NEXT CONTRIBUTING LOAD steps through all contributing loadcases from first level su perelements For each loadcase the contributing superelements are displayed with a separate colour The load factors are for each display printed on top of the col our coded superelements See explanation of FIRST CONTRIBUTING LOAD above Display the specified first level superelement with a separate colour in a display of the current higher level superelement See also the command SET GRAPHICS PRESENTATION COL OUR SUPERELEMENTS Superelement number Display the specified superelement alone Note that the current superelement is not changed by this option i e DISPLAY CURRENT SUPERELEMENT will revert to displaying the current superelement This option differs from LOCATE SUPERELEMENT in that only the specified superelement is displayed and it need not be a first level superelement SESAM Presel Program version 7 3 01 OCT 2004 5 23 EXIT EXIT PURPOSE The co
111. lso includes 11 For this superelement hierarchy to be correct superelement 31 must be created by ASSEMBLY NEW 31 and 11 included in 31 prior to including 11 in 21 21 can of course not yet be included in 31 because it does not yet exist Superelement 31 is therefore temporarily left incomplete and superelement 21 is created and completed by including 11 and 12 Then superelement 31 is completed by the commands ASSEMBLY OLD 31 and INCLUDE 21 twice This ensures that the occurrence of superelement 11 at the top of the table printed by Presel is assigned index 1 Index 1 for first ak AA 1 11 1 occurrence of 11 31 2 21 1 a Ma a IB 1 1 2 12 1 3 21 2 1311 3 2 312 2 Presel s table Manual sketch Figure 3 14 Awkward though correct superelement hierarchy 2 Incorrect Superelement Hierarchy If you were to create superelement 21 and include 11 and 12 first and thereafter create 31 and include 11 21 and 21 in that order the superelement hierarchy tabulated by Presel would be as shown in Figure 3 15 As seen index 2 of superelement 11 comes before index 1 when counting superelement 11 from top and down Note If you establish your load combination input based on these indexes then you will get wrong results for wave loads computed by Wajac and Wadam More specifically the load case num bering will not correspond to the indexes as described in Section 3 3 4 SESAM Presel
112. m Change X axis Node Tri Coordinate system Direct access Shortcut Command buttons commands menu last given input gt ie Sonne pate Line mode input Cursor position feedback prompt for information node number at cursor position shown here typed commands and data are echoed appear here Figure 3 2 The graphic mode window is composed of six different areas You may at this stage decide to go through a Presel tutorial Go then to Section 3 2 2 and use the explana tions below of the areas of the graphic mode window for reference The six different areas of the graphic mode window are used as follows e Graphic display area The model current or selected superelement is displayed here Within some commands e g the BOUNDARY command there is a need for selecting nodes Alter natively to keying in the nodes as explained in Section 5 1 you may select nodes by clicking or drag ging a rubberband in the graphic display area The availability of graphical selection is subject to that node selection has been switched on by the SET GRAPHICS NODE SELECTION command or by the Sel Node shortcut command button By default this is switched on Command menu The at any time allowable commands plus default values for numerical data are listed here as buttons Commands and values are selected by clicking the left mouse button LMB Slanted text signifies defa
113. mber of included superelements NS The identifies the X current superelement Figure 3 27 PRINT OVERVIEW OF SUPER ELEMENTS Presel SESAM 3 40 01 OCT 2004 Program version 7 3 BANDW STIFF MATRIX REDUCTION BY SESTRA SUPER EL FREE FREE SUPER MFLOP on 10MFLOP s per loadcase TYPE D O F S D O F S D O F S ESTIMATE DDD HH MM SS DDD HH MM SS MFLOP is the number of mil Here is given in days hours minutes lions of floating point opera and seconds the estimated reduction tions real number additions time per superelement for a processor multiplications etc performing 10 MFLOP per second Figure 3 28 PRINT CPU TIME ESTIMATES IN REDUCTION Table shows superelements included in ee this superelement assembly SUPER ELEMENT TYPE 100 LEVEL 3 SUP EL SUP EL MIR ROTATE ORIGIN TYPE INDEX LEVEL X Y X Y Z X Y Z 10 1 2 NO 0 0 0 0 0 0 0 000 0 000 0 000 10 2 2 YES 180 0 0 0 0 0 0 000 0 000 0 000 Figure 3 29 PRINT ELEMENT tabulates information on included superelements SUPER ELEMENT LEVEL 2 1 1 100 1 210 A coe ee bai 2 2 1 PRINT SUPER ELEMENT HIERARCHY 0 1 see the explanation of the command in section 5 3323 1 ties yet unconnected superelement hierarchies to E 2 10 2 1 1 2 gether in ROOT AA 2 2 2 PRINT SUPER ELEMENT HIERARCHY 100 1 branch number tabulates only the hierarchy including and below superelement number
114. mbling loads PARAMETERS CHANGE Changes a previously created location string for the superelement being included Not to be confused with the USE command see below CREATE Creates a location string for the superelement being included USE Modifies location strings for superelements forming the superelement being in cluded For example if the current superelement assembly is a fourth level su perelement and the superelement being included is a third level superelement then the command modifies location strings for the second and first level superelements forming the third level superelement DELETE Deletes a location string for the superelement being included oldloc Previously created location string to be changed or deleted newloc New location string replacing the previous one loc Location string assigned to the superelement being included refloc Location string s to be modified Wild cards may be used see notes below modloc The modified location string s Wild cards may be used see notes below NOTES The location strings are limited to eight characters The LOCATION USE command allows modifying location strings by use of wild cards The following modifications are allowed interpret the single characters in the examples as several characters refloc modloc E X replaces all strings by X A X replaces all strings ending with A by X A X replaces all strings beginning with A by X Presel 5 34 A A A A
115. ment Analysis Sn eee ac lt internal nodes rgi qa e rg COCO SUpernodes rgs lt SUpernodes ras PTA A lt internal nodes r aj A B Complete model Superelement First level superelements A and B superelement C hierarchy Figure B 2 Superelement Analysis Figure B 2 shows the same model as in the previous section but now it is divided into two superelements part models A and B which assembled constitute the complete model C Stiffness matrix displacement vector and load vector for each superelement are established K r4 Ry for superelement A Kg rg Rg for superelement B We now want to perform a reduction to eliminate the internal d o f s for both superelements r 4 and rg Let the following equation system be the equation of equilibrium of one of superelements A and B sub scripts A B are skipped Kr R B 3 This can be written in a partitioned form by sorting the d o f s of r so that all internal d o f s come first i denotes internal d o f s and s denotes super d o f s E Ae B 4 K Kss Es R Equation B 4 may be written as two separate equations Karit Kir R B 5 1 Kir a K r R 189 S Equation B 5 may be solved with respect to r SESAM Presel Program version 7 3 01 OCT 2004 APPENDIX B 3 1 1 r K Kar K R B 7 This inserted in Equation B 6 yields To 1 Fal Kss K
116. ments On the other hand if you want to analyse several non coupled models for example to test various meshes or designs for the same structure you may find it convenient to make a single model comprised of non coupled superelements and analyse all these in one operation one Sestra run This approach should not be employed for large models e You also need to consider which load cases to create for the first level superelements and how to com bine these through the higher level superelements to create the final loads for the top level superelement SESAM Presel Program version 7 3 01 OCT 2004 3 43 Why bad The superelements are too small The superelements are not compact in order to limit number of supernodes The order of including superelements in the higher level superelement should not be haphazard but rather follow a topological sequence A superelement the one at the bottom in the upper sketch and the vertical one in the lower sketch is coupled to several other superelements Do not assemble superelements not geometrically coupled no holes in the superelement assembly Bad avoid if possible Good or better Figure 3 32 Good and bad superelements 3 10 Node Numbering Optimization to Minimise the Bandwidth Sestra offers two equation solvers the traditional Supermatrix solver and the Multifront solver a more recent and highly efficient solver The Multifront solver
117. mmand interrupts the program execution All files opened are properly saved and closed The user may resume the superelement assembling at a later stage by referring to the model file and command log file as old when re entering Presel Presel SESAM 5 24 01 OCT 2004 Program version 7 3 HELP GENERAL SYNTAX SPECIAL KEYS STATUS LIST SUPPORT HELP PURPOSE The command provides information on various subjects Except for the STATUS LIST option the informa tion is printed in the message window PARAMETERS GENERAL SYNTAX Information on how to enter commands and text is provided SPECIAL KEYS Information on some special keys is provided STATUS LIST This command is obsolete See Section 1 4 for looking up information in the Status List SUPPORT The telephone and facsimile numbers and the Internet address for requesting sup portis printed together with detailed information on the program version used This information is of importance in connection with support requests SESAM Program version 7 3 INCLUDE 01 OCT 2004 INCLUDE supno CHECK INCLUDE DECODE T MATRIX DISPLAY DISTANCE CHECK END DO NOT INCLUDE LOCATION MIRROR NOPRINT CHECK INCLUDE PERFORM INCLUDE POSITION PRINT INV T MATRIX PRINT T MATRIX RESET T MATRIX ROTATE TRANSLATE PURPOSE Presel 5 25 The command starts the process of
118. mmands themselves B A D y 4p f The characters A B C and D in the examples above represent parameters being COMMANDS written in upper case and numbers written in lower case All numbers may be entered as real or integer values Brackets are used to enclose optional parameters Presel SESAM 5 2 01 OCT 2004 Program version 7 3 Note The command END is generally used to end repetitive entering of data Using double dot rather than END to terminate a command will depending on at which level in the command it is given save or discard the data entered Generally if the data entered up to the double dot is complete and self contained the double dot will save the data If in doubt it is always safest to leave a command by entering the required number of END commands 5 1 Node Select Features Selection of nodes is required in several commands e g in the BOUNDARY and TAG commands Nodes may be selected by line mode commands as well as by graphical means 5 1 1 Line mode Selection You may by line mode commands select e Several nodes by referring to their node number triplets and enclosing them in parentheses A SINGLE node by referring to its node number triplet This option is less relevant after introduction of the previous option of enclosing node number triplets in parentheses A GROUP of nodes by referring to the triplet of the first node plus the last node number and the step inc
119. mory is allocated when Presel is started and the amount is fixed until exiting the program The amount of memory allocated can be changed by editing the configuration password file To change the amount insert or modify the line MSIZE PRESEL BUFFER buffer bytes where buffer bytes represents the amount of memory Presel will allocate in bytes The default value is 2457600 2 4576 millions representing 150 buffers of 16384 bytes each The buffer should be changed 1f for example there is not enough memory to use the graphical user interface Note however that in creasing the memory for buffers will not improve performance much Working array for node number optimization SESAM Presel Program version 7 3 01 OCT 2004 4 7 You may limit the size of the working array used for optimising the node numbering of a higher level su perelement by defining the parameter MSIZE PRESEL OPTIMIZE in the configuration password file If you do not give any value for this parameter then as much memory as needed will be allocated e Memory for graphical user interface The graphic mode window will use memory and allocate it when needed Large displays will need more memory than small displays Typing While typing a command using the keyboard you cannot click commands in menus or select nodes by click ing or use the mouse in any other way until the Return key has been hit or until the typed text has been deleted by backspace Pres
120. mpatible between different versions of Presel The command log file may however be used as input to a new version 4 1 4 Creating Plots for Reports The CGM plot format see the SET PLOT FORMAT command is well suited for importing SESAM plots into reports produced by MS Word and other word processors You may also transfer CGM files from one operating system to another just make sure to use the binary option when transferring the file with FTP or another protocol Depending on the capabilities of your word processor the PostScript plot format may also be used for the purpose of importing SESAM plots into reports Contrary to CGM PostScript is an ASCII formatted file and is therefore more easily transferred from one computer make to another Note that a word processor will normally recognise only one picture display on each file You should therefore specify a new file name for each plot command using the SET PLOT FILE command 4 1 5 Command Line Arguments It is possible to specify command line arguments when starting Presel A command line argument will influ ence the program execution in various ways The command line arguments are PREFIX text General file name prefix SESAM Program version 7 3 NAME text STATUS text INTERFACE LINE INTERFACE PICK HEADER NONE NOHEADER HEADER SHORT WRITE SUPERELEMENT number NOWRITE SUPERELEMENT COMMAND FILE filename NOCOMMAND FILE FORCED EXIT N
121. n 3 8 and Section 3 9 Chapter 4 EXECUTION OF PRESEL contains more special information not intended for the new user using Manager to control his SESAM analysis The chapter explains how to start Presel outside Manager and operate it in line mode not using the graphical user interface The files used by Presel are also explained Practical information is provided on how to operate Presel and manipulate its files in various ways Built in and hardware dependent requirements and limitations are also described Chapter 5 COMMAND DESCRIPTION explains in detail all commands of Presel The commands and sub commands are sorted alphabetically Appendix A TUTORIAL EXAMPLES provides input to Prefem for creating the first level superelements used in the tutorials of Chapter 3 USER S GUIDE TO PRESEL Appendix B THEORY explains the mathematical foundation of the superelement technique 1 4 Status List There exists for Presel as for all other SESAM programs a Status List providing additional information This may be e Reasons for update new version New features Errors found and corrected e Etc To look up information in the most updated version of the Status List go to the support page of our website click the SESAM Status Lists link and log into this service Contact us for log in information SESAM Presel Program version 7 3 01 OCT 2004 2 1 2 FEATURES OF PRESEL Presel is a program for assembling superelements part models
122. n 7 3 Load case 4 Weight of snow on roof this is a house in Norway Load case 5 Weight of people and furniture on floors In the input for assembling the loads you refer to a single first level superelement occurrence by giving its name and location string and to several occurrences by using wild card notation ASSEMBLY OLD 100 LOAD ASSEMBLY Load 1 is self weight gravity 1 INCLUDE LOAD 1 1 0 oe Load 2 is wind pressure on south walls both long and short walls NCLUDE LOAD WALL SOUTH 2 1 0 Z U ole l l l NCLUDE LOAD LWALL SOUTH 2 1 0 DE LOAD SWALL NORTH 2 1 0 Z Q H C EN eight of snow on roof NCLUDE LOAD ROOF BASIC 2 1 0 END Load 5 is weight of people and furniture on floors there are 50 more people and furniture in ground floor than in first floor 5 INCLUDE LOAD FLOOR BASICGRD 2 1 5 INCLUDE LOAD FLOOR BASICI1ST 2 1 0 END uU oo l l l Load 4 is I W E Load 3 is wind pressure on south long wall and north short wall I T W E oe l l l oo END END e Global load case 1 gravity will include local load case from all first level superelements e Global load case 2 wind pressure on south walls will include local load case 2 from the superelements long and short walls WALL located to the south and including both storeys SOUTH Etc The command will establish the load combinations required o
123. n all levels from the second level and to the top This can be verified by printing the load combinations for the various higher level superelements Note The LOAD ASSEMBLY command will typically create more load combinations for interme diate level superelements between first and top level than you normally will create by the more manual one by one and group methods Such extra load combinations for intermediate level superelements will not make any difference except for spending somewhat more compu ter time and disk space Note In the above example location strings are only given for first level superelements and loads are assembled from first level directly to the top level You may also assemble loads to intermedi ate level superelements You then need to combine loads from these intermediate level superelements to the top by either the assembly or one by one method SESAM Presel Program version 7 3 01 OCT 2004 3 33 3 4 4 Advice on Giving Unique Identifications to Superelement Occurrences The house example of Section 3 4 2 and Section 3 4 3 illustrates how name and location strings uniquely identify superelement occurrences The LOCATION CREATE command assigns location strings to first level superelements when these are included into second level Thereafter the LOCATION USE command modifies these location strings of first level superelements during the assembling of third and higher level superelements The wild card notation allows t
124. n depth dis cussion cannot be provided here Efficient application of the technique rely on a combination of an under standing of the theoretical foundation consideration of the hardware being used and practical experience Discussing with experienced users and taking heed of the following advice will enable you to take advan tage of the superelement technique in an efficient way while building up your own practical experience Some of the items below contradict each other to some extent this only underlines the fact that you often have to balance between conflicting considerations Also see Figure 3 32 for illustrations of some of the items below How to split the structure into superelements Utilise the possibility to repeat superelements Both first and higher level superelements may be repeated Repetition is possible whenever two or more parts of the structure are geometrically equal Remember that superelements may also be mirrored Make first level superelements as large as possible limited though by the capacity of your computer The two items above combined implies that there is a limit to how small the superelements should be to enable repetition before the gain is outweighed by loss in other ways e g administration of many superelements and heavy higher level superelements Presel SESAM 3 42 01 OCT 2004 Program version 7 3 Very small superelements will often be a disadvantage in the postprocessing
125. ned within the LIN EAR DEPENDENCY command Note that only supernodes or super d o f s will appear as nodes or d o f s in the higher level superele ments into which this superelement is included All other boundary conditions involve that the node or d o f will not exist at higher level superelements See Section 3 2 6 for more information on this Nodes for which no boundary conditions are given will by default have all its d o f s as FREE A node may have less that six d o f s This will for example be the case for membrane models in which the nodes have three d o f s Another example is when not all six d o f s were defined as super for the included lower level superelement s When boundary conditions are given for such nodes the boundary conditions for non existent d o f s will be ignored If for example only the translations in X and Y and the rotation about Z exist the node is fixed by the sequence FIX FIX FIX where means that any legal boundary condition may be given it will be ignored anyway Presel SESAM 5 10 01 OCT 2004 Program version 7 3 A node for which boundary conditions previously has been given will not be affected by a new boundary command that includes the node in question Le boundary conditions are neither overwritten nor accummulated The only way to given a node new boundary conditions is to delete the current conditions using the DELETE command and then redefine them The boundary condi
126. o be multiplied by a three by three transforma tion matrix these matrices must for all nodes include either all three translational d o f s or all three rota tional d o f s or all six d o f s In other words to rotate or mirror a superelement only these three alternative selections of super d o f s for a node are allowed Any other selection of the six d o f s of a node to be super will only allow the superelement to be translated when being included in an assembly For more information on the superelement technique see the Sestra documentation
127. odel about a screen horizontal axis and move left and right to rotate about a screen vertical axis A circular motion will rotate the model about an axis normal to the screen in the opposite direction of the circular motion When the LMB is released the model is dis played in its new position The X axis Y axis and Z axis buttons display the model as seen along the model s X Y and Z axis respectively The Default button switches back to the default viewing position optionally set in Manager and re displays the model The Zoom In button zooms in by either clicking twice and diagonally or by pressing the LMB and dragging it to form a zoom area rubberband box The Zoom Fr button re displays the model so that it fits within the display area The Learn button offers making a new Shortcut command Click the button and enter a maximum eight character string being the name of the new Shortcut command and hit Return Now give any sequence of commands Several complete commands may be given the last of which may be incom plete i e more data is required to make it complete Clicking the Learn button once more completes the process and the new Shortcut command appears as a new button The button accepts all available default commands and parameters The button aborts the current command The button accepts a single default value i e the one shown in slanted font The Node bu
128. of the new model file The file name of the new model file NEW means that the model file will be created starting a new session from scratch OLD means that it exists already contin uing an earlier session Set various parameters controlling the plot The command is described in detail in the following Set various parameters controlling the print The command is described in detail in the following Specify a unit vector tolerance used for deciding whether two vectors span a plane and whether a matrix is orthonormal The unit vector tolerance without unit has default value 0 001 Presel 5 70 SESAM 01 OCT 2004 Program version 7 3 SET GRAPHICS GRAPHICS ALTERNATIVE SCREEN DEVICE AUTO BASIC ELEMENT MODE SOFTWARE CHARACTER TYPE HARDWARE BOUNDARY CONDITION ELEMENT LINES INCLUDED SUPERELEM COLOUR colour tone NODE NUMBER NODE SYMBOL SUPER NODES DEVICE device name EYE DIRECTION eyex eyey eyez ON HIDDEN OFF ON INPUT OFF ON NODE SELECTION OFF PLOT FILE prefix filnam ON COLOUR SUPERELEMENTS OFF PRESENTATION ON FILLED ELEMENT OFF ON SCALING AUTOMATIC OFF SHRINK FACTOR shrinkfac BOUNDARY CONDITION SYMBOLS LOAD NUMBERS NODE NUMBERS SIZE SYMBOLS size NODE SYMBOLS ONE NODED ELEMENT SYMBOLS ORIGIN SYMBOL SESAM Program version 7 3 PU
129. ons the superelement by referring to three points or nodes of the superelement assembly and the corresponding three points or nodes of the superelement being included The three points nodes of the assembly are given first The two sets of three points nodes must form a triangle and they must be congruent If the COORDINATE alternative is chosen the point does not have to correspond to a node The coordinates are given in the coordinate systems of the assembly and superelement being included respectively The POSITION sub command cannot be used if transformations have already been specified for the superelement being included Use the RESET T MATRIX sub command in such case Original position Y The superelement assembly After positioning Figure 5 7 POSITION by two sets of three nodes or points PARAMETERS NODE Refer to a node triplet supno index nodeno The node number triplet COORDINATE Refer to a point by using coordinates xyz The point coordinates SESAM Presel Program version 7 3 01 OCT 2004 5 39 INCLUDE supno PRINT T MATRIX PRINT INV T MATRIX PRINT T MATRIX PRINT INV T MATRIX PURPOSE The sub commands print the transformation matrix of the superelement being included This 3 by 4 matrix is an accumulation of all translations rotations and mirrorings given for the superelement The first three columns of the transformation matrix a 3 by 3 matrix constitute the cosine matrix rota tion
130. practical and efficient use of the superelement technique On the other hand 1f a higher level superelement is created by assembling superelements in a haphazard way in effect this is the way the automatic assembling of superelements in Pretube works optimising the higher level superelements may be important SESAM Presel Program version 7 3 01 OCT 2004 4 1 4 EXECUTION OF PRESEL This section provides information on How to start Presel Line mode input syntax e Files used e Creating plots for reports e Alternative execution modes Program requirements Program limitations 4 1 Program Environment Presel is available on Microsoft Windows 4 1 1 Starting Presel from Manager Presel is started from Manager by first setting the type of analysis to be superelement analysis click Options Superelement and then clicking Model Superelement handling Presel The graphical user interface of Presel is explained in Section 3 1 4 1 2 Line Mode Input of Commands and Arguments The syntax and characteristics of line mode input are as follows Presel SESAM 4 2 01 OCT 2004 Program version 7 3 The parameters commands sub commands and data are separated by one or more blank characters or a comma and may be entered one by one or with two or more entries on a single line of input For exam ple COMMAND SUB COMMAND SUB SUB COMMAND data is equivalent to COMMAND SUB COMMAND SUB SUB COMMAND data Note howeve
131. r Nodes are to be selected now Select nodes see Section 5 1 Refers to previously selected tagged nodes see the TAG UN TAG commands SESAM Presel Program version 7 3 01 OCT 2004 5 63 UNTAGGED Refers to all but the previously selected tagged nodes see the TAG UNTAG commands ALL LOADCASES Print all information for all load cases OVERVIEW Print an overview for a selected load case or for all load cases Presel SESAM 5 64 01 OCT 2004 Program version 7 3 PRINT NODE BOUNDARY CONDITIONS SELECT select nodes COORDINATES TAGGED NODE Se LINEAR DEPENDENCY UNTAGGED NUMBER END PURPOSE The command prints nodal data for the current superelement Note that you may change the print format for real numbers FORTRAN E F or G formats by the SET PRINT FORMAT command E format is the default choice PARAMETERS BOUNDARY CONDITIONS Print boundary conditions for selected nodes It is possible to switch between text and digits for boundary condition codes by the SET PRINT TABLE NODE BOUNDARY TABLE com mand The boundary condition codes used in the print table are described in Table 5 3 Table 5 3 Boundary condition codes of individual d o f in print table Digit Text Boundary condition of d o f 1 X d o f does not exist node has reduced number of d o f s 0 blank free 1 FIXED fixed at zero displacement PRESC prescribed displacement 2 3 LIN
132. r that data belonging to different data sets cannot be entered on a single line UPPER CASE lower case all commands will be logged on a command log file in UPPER case e Commands and sub commands may be abbreviated as long as they are unique In a command consisting of words separated by hyphens each word may be abbreviated or completely left out Examples NODE NUMBERS N N COMMAND INPUT FILE C I e Default values are provided between slashes default The defaults are accepted by hitting Return Real or integer input may be entered irrespective of type of numerical data use E for exponent e lt will list all legal commands and data options This command is irrelevant for the graphical user inter face where all legal commands and data options are at any time given in the command column of the graphic mode window e P will list all legal commands starting with P e two dots will execute the input data before and subsequently abort the current command The program is thereafter ready for more commands If the data before the is incomplete it will be dis carded lt two commas will cause one default parameter to be accepted May be useful when editing a com mand input file e semicolon will cause default parameters to be accepted until the end of the parameter group or until there is no default provided Text containing blank charact
133. r B as explained in Figure 3 25 B is computed based on the projection of the dependent node onto the line between the two independent nodes Normally the two node dependency has physical meaning only when the dependent and the two independ ent nodes all lie on a straight line _ dependent node b B b a b independent node 1 independent node 2 Figure 3 25 Two node linear dependency the dependency factor B SESAM Presel Program version 7 3 01 OCT 2004 3 37 Note Dependent nodes are indicated by blue triangles in the model display Note Independent nodes supernodes are indicated by blue octagons will look like circles All independent d o f s must be super d o f s i e they are defined with boundary condition code super using the BOUNDARY command prior to giving the LINEAR DEPENDENCY command The two node dependency alternative also allows the user to define the independent nodes as super within the command by the FORCE INTO SUPER alternative This implies that introducing linear dependency for a superele ment involves that the superelement must be included in yet a higher level superelement The requirement that the independent d o f s must be super only concerns second and higher level superele ments as created by Presel In the case of first level superelements created by Preframe and Prefem the inde pendent d o f s need not be super provided that the Multifront equation solver is used in Sestra
134. r the GLOBAL COORDINATES nor the USE COORDINATE SYSTEM space is given the former is valid The points defining the lines planes and volumes may as shown by the table explaining point above either be nodes selected by giving node number triplets or specified by coordinates When a cylindrical coordinate space has been referred to by USE COORDINATE SYSTEM in a selection sequence the point coordinates may optionally be given in this cylindrical coordinate system the LOCAL COORDINATE option Note that the choice between COORDINATE and LOCAL COORDINATE is merely for giving the point coordinates The line plane or volume is still interpreted in the global cartesian or given cylindrical space according to the choice between GLOBAL COORDINATES and USE COORDI Presel 5 4 01 OCT 2004 NATE SYSTEM Normally though you want to use the LOCAL COORDINATE option when the line plane or volume is interpreted in a cylindrical coordinate space and the COORDINATE option when they are interpreted in the cartesian space Note You may also use the TAG command to pre select nodes and refer to these TAGGED nodes SESAM Program version 7 3 rather than selecting nodes directly within the command in question X Global cartesian coordinates bounded cy Straight LINE infinite and bounded Cylindrical coordinates infinite th EE x 2nd pnt Infinite PLANE defined by 3 points dots or 2 points X es
135. rement in node numbering All nodes on a straight LINE infinite or a segment by referring to two points e All nodes in an infinite PLANE by referring to either three points in the plane 3 PLANE option or one point in the plane and one point on a vector perpendicular to the plane 2 PLANE option All nodes inside a VOLUME by referring to two points being the diagonally opposite corners of a box with side surfaces parallel with the coordinate system planes XY YZ and ZX or parallel interpreted in the space of the named coordinate system if the USE COORDINATE option has been chosen All nodes belonging to a previously defined set Several nodes by repeatedly using any of the above selection methods stop selection by END ALL nodes Whether a certain node lies on the given straight line or lies in the given plane or is located within the given volume is decided by a coordinate tolerance see the SET COORDINATE TOLERANCE command 5 1 2 Graphical Selection In addition to the above line mode commands you may select nodes graphically by clicking or dragging a rubberband Such graphical selection is logged as the line mode command by which you enclose the triplets of several nodes in parentheses When dragging a rubberband you do not even need to type in the enclosing parentheses as these are filled in by the dragging operation SESAM Presel Program version 7 3 01 OCT 2004 5 3 Also whenever a single node is
136. rs from the direct access buttons in that they are for command logging and input purposes Logging is subject to use of the SET JOURNALLING GRAPHICS command The FRAME option makes the displayed model fill the graphic area For the IN and OUT options use the mouse left mouse button to give the zoom area You may either e press and hold while dragging to the opposite corner of a rectangle and then release or e click first one corner of a rectangle and then click the diagonally opposite corner The actual zoom area is the smallest square containing the rectangle ZOOM IN will magnify the part of the picture that is inside the zoom area ZOOM OUT will fit the picture into the zoom area Presel SESAM 5 84 01 OCT 2004 Program version 7 3 ncomnd ALL PURPOSE The command reads commands from the command input file The command input file is opened by the command SET COMMAND INPUT FILE The command input file may be a command log file from a pre vious run or a file prepared by a text editor The program will execute commands from the command input file until e an end of file is detected e a is found on the file ncomnd number of commands have been read or an erroneous command sequence is found PARAMETERS ncomnd Number of commands to be read from the command input file ALL All commands are read from the command input file SESAM Presel Program version 7 3 01 OCT 2004 APPENDIX A 1 APPEND
137. rted the SESAM Manager and that first level superelements have already been cre ated then do as follows e Click Options Superelement and within the window appearing set your analysis to be superelement analysis as opposed to direct analysis and specify top level superelement number any number may be used e Start Presel by clicking Model Superelement Handling Presel and click OK in the window then appearing The main part of the graphical user interface is the graphic mode window There are also a print window and a message window Print requested by the user appears in the print window whereas various program messages appear in the message window Figure 3 1 illustrates the three Presel windows Graphic mode window Print window Message window Figure 3 1 The Presel windows Presel offers two modes of input and both are available in the graphic mode window e Line mode input i e typing commands and data using the keyboard e Graphic mode input i e selecting commands by clicking the left mouse button LMB A sketch of the graphic mode window is shown in Figure 3 2 together with explanations of the six different areas How to use the areas is explained in more detail in the following SESAM Presel Program version 7 3 01 OCT 2004 3 3 click left mouse button LMB to select command or action Graphic display area View Label Assembly Pan Node Sym Boundary Rotate Supn Sy
138. s If you want to run this example through Presel you first need to create the first level superelements employed Appendix A TUTORIAL EXAMPLES Section A 2 provides the input for these first level superelements Refer to Section 3 2 2 for how to start Presel In this case set top level superelement to 100 In this tutorial five first level superelements shall be assembled to form a house as illustrated by Figure 3 17 SESAM Presel Program version 7 3 01 OCT 2004 3 25 LP An a i Y 2 4 superelement foundation name is FNDT 3 Y superelement 2 long wall superelement 3 short wall name is LWALL name is SWALL Lio superelement 4 floor superelement 5 roof name is FLOOR name is ROOF LWALL SWALL second level superelement 10 E name is STOREY cards superelement 100 the complete model name is HOUSE LWALL FLOOR Y SWALL Figure 3 17 First second and top third level superelements After reading the first level superelements into Presel the first task is to assign names by the commands ASSEMBLY OLD 1 NAME CREATE FNDT ASSEMBLY OLD 2 NAME CREATE LWALL ASSEMBLY OLD 3 NAME CREATE SWALL Presel SESAM 3 26 01 OCT 2004 Program version 7 3 ASSEMBLY OLD 4 NAME CREATE FLOOR ASSEMBLY OLD 5 NAME CREATE ROOF Then the second level superelement 10 is created and given its name names for higher level superelements are normally not required but included here for complet
139. s between the coordinate systems of the superelement being included and the superelement assembly The fourth column describe the translations between the systems The conversion of coordinates from one system to the other is done by adding a row of zeros to the transformation matrix to make it a 4 by 4 matrix and adding a fourth term being equal to to the coordinate vectors as follows ZN RY II S O we E p PARAMETERS PRINT T MATRIX The transformation matrix is printed The relation between the coordinate systems of the superelement being included and the superelement assembly is C TxC Where C is the coordinates in the assembly coordinate system and C is the coordinates in the superelement s coordinate system PRINT INV T MATRIX The inverted transformation matrix T is printed Presel SESAM 5 40 01 OCT 2004 Program version 7 3 INCLUDE supno RESET T MATRIX RESET T MATRIX PURPOSE The sub command resets the transformation matrix containing the accumulated translations rotations and mirrorings of the superelement being included This means that the superelement being included is brought back to its original position with its coordinate system overlapping the coordinate system of the superele ment assembly It is then ready for new transformations SESAM Presel Program version 7 3 01 OCT 2004 5 41 INCLUDE supno ROTATE X AXIS GL
140. s and sub commands are described in alphabetic order Below is a list of all main basic level commands ASSEMBLY BOUNDARY CHANGE COORDINATE SYSTEM DEFINE DELETE DISPLAY EXIT HELP INCLUDE LABEL LINEAR DEPENDENCY LOAD NAME OPTIMIZE PLOT PRINT See page 5 8 See page 5 9 See page 5 11 See page 5 14 See page 5 16 See page 5 17 See page 5 21 See page 5 23 See page 5 24 See page 5 25 See page 5 44 See page 5 46 See page 5 50 See page 5 56 See page 5 57 See page 5 58 See page 5 60 SESAM Program version 7 3 READ ROTATE SET TAG TASK TRANSFORMATION UNTAG WRITE ZOOM 01 OCT 2004 See page 5 66 See page 5 67 See page 5 68 See page 5 78 See page 5 79 See page 5 80 See page 5 81 See page 5 82 See page 5 83 See page 5 84 Presel 5 7 Presel SESAM 5 8 01 OCT 2004 Program version 7 3 ASSEMBLY NEW ASSEMBLY supno OLD PURPOSE This command creates a new superelement and makes it the current one the NEW option or an exist ing superelement is made the current one the OLD option A NEW superelement will be empty until one or more superelements are included into it It will then become a second or higher level superelement On OLD superelement is either e A first level superelement typically created by Preframe or Prefem and already read into Presel A higher level superelement previously created by Presel The curr
141. s at DISPLAY CURRENT SUPERELEMENT first level are free LABEL NODE SYMBOL ALL f g nodes at second level The screen display will in principle be as shown above Encircled superelement numbers are added here for pedagogic purposes An origin symbol may be added by the LABEL ORIGIN SYMBOL command Figure 3 4 The commands and resulting superelements SESAM Presel Program version 7 3 01 OCT 2004 3 9 Superelements as shown by DISPLAY commands INCLUDE 6 DISPLAY ROTATE GLOBAL AXIS Z 90 TRANSLATE 4 4 0 DISPLAY 2 lt __ 2 superelements NOPRINT CHECK INCLUDE bb b b 3 are coupled here PERFORM INCLUDE 242 42 42 43 END al 3 superelements DISPLAY CURRENT SUPERELEMENT aS are coupled here LABEL NODE SYMBOL ALL COUPLED NODES Only 1 superelement is coupled here Node number triplets for a node Sia die 1 G1 DA Ge 20 2 LABEL NODE NUMBERS NODE NUMBER TRIPLET aa ALL NODE NUMBER TRIPLETS sup 6 index 2 sup 5 index 1 Node number triplet 6 2 10 The LABEL NODE NUMBERS command above results in all node number triplets for all nodes to be shown To avoid cluttering the figure triplets for two nodes only are shown A triplet is composed of three numbers The triplet 5 1 7 is composed of 5 first level superelement number 1 superelement index and 7 node number See following sections on superelement index and node number triplets Figure 3 5 The commands and resulting superelements continued
142. sel Program version 7 3 01 OCT 2004 3 35 To get this third level superelement see alternative 1 above Dass 30 Fourth level superelement 40 includes 30 twice second level 3 inclusion is mirrored about a vertical west east plane First level superelement 10 is also included directly Location strings are modified and created by LOCATION USE AC EN LOCATION USE BC NE LOCATION USE BD NW LOCATION USE AD WN LOCATION USE AC ES LOCATION USE BC SE LOCATION USE BD SW LOCATION USE AD WS LOCATION CREATE EE for hatched area for shaded area for blank area Figure 3 24 Location string convention alternative 3 3 5 Boundary Conditions Boundary conditions are defined for the six degrees of freedom d o f s of a node individually Using the BOUNDARY command you can define the following boundary conditions e Free the d o f is free to displace this is the default boundary condition for all d o f s of all nodes e Fixed the d o f is fixed at zero displacement e Prescribed the d o f is fixed at a given displacement given by the LOAD NODE command e Super A superelement can only be included in a superelement assembly if one or more of its nodes or d o f s are defined as super If one or more of the nodes d o f s of a superelement are super the superelement cannot be the top level superelement the complete model It must be included in a higher level assembly In the BOUNDARY command you need to select no
143. sitions A B and C Case 1 rotating Position and loads after rotation i B Wi ee y88 Original position and loads ee 7 shown in broken lines hee j aa gt C Case 2 mirroring Original position and loads shown in broken lines Position and loads after mirroring Figure 3 10 Loads are rotated and mirrored along with the superelement SESAM Presel Program version 7 3 01 OCT 2004 3 17 3 3 4 Combining Wave Loads by the Group Method This method for combining loads is quite general Nevertheless it is explained below with reference to a structure subjected to wave loads an offshore or a ship structure as this is the typical example in SESAM A model is typically comprised of several superelements Wajac or Wadam are employed for computing a number of wave loads e g 8 wave directions and 12 wave frequencies for each direction altogether 96 load cases for each occurrence of all superelements Combining all these load cases for all these superelements through all the superelement levels to the top will require a considerable amount of input The LOAD COM BINATION GROUP command reduces this input to a manageable amount Note Wave loads computed by Wajac and Wadam are stored on Loads Interface Files the L FEM files These files are not read by Presel This means that the load combination whether this is done by the one by one group or assembly method is performed without the progr
144. st north NE means north east NW means north west etc Figure 3 23 shows a scheme arriving at this more logical convention for location strings First level superelement 10 is given name TRIANGLE N ws E 10 Second level superelement 20 includes 10 twice first level 1 with no translation rotation secondly with 180 rota S tion Location strings are assigned by LOCATION CREATE A for shaded area LOCATION CREATE B for blank area location 20 strings level 2 Third level superelement 30 includes 20 twice second inclusion is mirrored about a vertical south north plane Location strings are modified by LOCATION USE A EN LOCATION USE B NE LOCATION USE A WN LOCATION USE B NW for blank area for shaded area 30 level 3 Fourth level superelement 40 includes 30 twice second inclusion is mirrored about a vertical west east plane First level superelement 10 is also included directly Location strings are modified and created by no modifications for shaded area LOCATION USE N S 1 LOCATION USE N S LOCATION CREATE EE for hatched area for blank area Figure 3 23 Location string convention alternative 2 Note If you are unable to device an easy scheme for arriving at the chosen convention for naming location strings you may always resort to the scheme shown in Figure 3 22 up to the top level and for the top level substitute the location strings with the proper ones See Figure 3 24 SESAM Pre
145. superelement 7 index 1 The 96 global load cases gt 1 2 3 96 This is the second load case i in WAJAC Compare with WADAM as a MA A EA pa oe 8 1192 superelement 5 index superelement 6 index 1 superelement 6 index 2 Figure 3 11 Wajac s numbering of load cases for superelement occurrences Presel SESAM 3 18 01 OCT 2004 Program version 7 3 superelement 7 index 1 The 96 global load cases gt 1 2 3 96 This is the second load case in WADAM Compare with WAJAC l 2 Als LO l 3 STER AAA D EA 2 4 0 see 192 superelement 5 index 1 superelement 6 index 1 superelement 6 index 2 Figure 3 12 Wadam s numbering of load cases for superelement occurrences Load Combination Group for Wajac Figure 3 11 illustrates how the load cases for the superelement occurrences must be combined to establish the global loads The one by one method for combining loads computed by Wajac will for superelement 7 be glc sup indx llc factor LOAD COMB 1 5 de 1 L O END 6 1 1 0 END 6 2 97 0 END END 2 5 1 2 1 0 END 6 1 2 0 END 6 2 98 0 END END 3 5 1 3 1 0 END 6 1 3 0 END 6 2 99 0 END END etc for each global load case up to the last one 96 5 de 96 1 0 END 6 1 96 1 0 END 6 2 192 1 0 SESAM Presel Program version 7 3 01 OCT 2004 3 19 END END END END As can be seen the one by one method involves a lot of input 24
146. symbol showing where the origin is located supernode at least one of the d o f s in the node is a super d o f linearly dependent node free node the translational d o f is fixed at zero displacement the rotational d o f is fixed at zero displacement both the translational and rotational d o f s are fixed at zero displacement the position of origin and the axes Symbols produced by the LABEL command Presel SESAM 5 46 01 OCT 2004 Program version 7 3 LINEAR DEPENDENCY GENERAL NODE DEPENDENCY TWO NODE DEPENDENCY END LINEAR DEPENDENCY PURPOSE The command defines the displacements of selected nodes to be linearly dependent of displacements of other selected nodes See also Section 3 6 The GENERAL NODE DEPENDENCY option couples any d o f of a node the dependent d o f to any other d o f s of any other nodes the independent d o f s The TWO NODE DEPENDENCY option couples all d o f s of a given node to the corresponding d o f s of two other nodes Linear dependencies involves that the dependent d o f s get the boundary condition LINEAR and the inde pendent d o f s get the boundary condition SUPERL super due to linear dependency A SUPERL d o f will appear in the next level superelement in the same way as a SUPER d o f There are certain rules as con cerns the boundary condition of a d o f before and after the definition of a linear dependency and whether the linear dependency can at all be de
147. tem that can be referred to when defin ing boundary conditions and when selecting nodes presently limited to cylindrical defines sets displays superelements and contributions to load combinations provides information on the command syntax and how to get technical support The command also launches the Status pro gram providing access to the Status List of Presel includes a superelement in the current higher level superele ment assembly annotates node symbols node numbers etc to the displayed su perelement makes one or more degrees of freedom d o f s linearly de pendent on one or more other independent d o f s defines nodal loads and load combinations gives aname to a superelement This is only relevant in connec tion with the LOAD ASSEMBLY command optimises the node numbering in order to minimise the band width of the stiffness matrix of higher level superelements generates a plot file of the current display The plot file may be printed or imported in a word processor In a MS Windows en vironment the plot may also be directed to an on line printer prints tables over model data The tables may be directed to the screen or to a file by the SET PRINT command reads Input Interface Files containing descriptions of first level superelements SESAM Presel 01 OCT 2004 2 3 Program version 7 3 ROTATE rotates the display of the superelement SET sets and defines various control parameters TA
148. times the amount given above even for such a small superelement hierarchy For a large superelement hierarchy the amount of input will increase many times The group method involves considerably less input lowglc higlc step sup indx lowllc factor LOAD COMB GROUP 1 96 1 5 1 1 1 0 6 1 1 1 0 6 2 97 1 0 END END END This command says that global load cases 1 to 96 with step 1 will be created The superelement occurrences sup indx 5 1 6 1 and 6 2 will contribute to these global load cases For each occurrence only the local load case lowllc corresponding to the first global load case is given i e 1 1 and 97 for the three occur rences respectively Implicitly the command says that the global load cases 2 3 etc are defined by incre menting the local load cases in parallel Also see the description of the LOAD COMBINATION command in Chapter 5 The LOAD COMBINATION GROUP command must be given for each higher level superelement Still the amount of input is manageable Load Combination Group for Wadam Figure 3 12 illustrates how the load cases for the superelement occurrences must be combined to establish the global loads The one by one method for combining loads computed by Wadam will for superelement 7 be glc sup indx lle factor LOAD COMB T 5 1 1 1 0 END 6 1 1 L O END 6 2 2 L O se END END 2 5 1 2 1 0 END 6 1 3 0 END 6 2 4 0 ia END END 3 5 1 3 1 0 END 6 1 5 0 END 6 2
149. tions may be given both in a rotated cartesian coordinate system the TRANSFORMA TION option and a cylindrical coordinate system the LOCAL COORDINATE SYSTEM option Both these systems must previously have been defined by the TRANSFORMATION and COORDINATE SYS TEM commands respectively The boundary conditions may be verified by the LABEL BOUNDARY CONDITION SYMBOL and the PRINT NODE BOUNDARY CONDITIONS commands Boundary conditions are deleted by the DELETE BOUNDARY command PARAMETERS fixcode 0 FREE 1 FIXED 3 PRESCRIBED and 4 SUPER GLOBAL The boundary conditions are specified in the global coordinate system LOCAL COORDINATE SYSTEM The boundary conditions are specified in a cylindrical coordi nate system coord name The name of the cylindrical coordinate system previously de fined by the COORDINATE SYSTEM command TRANSFORMATION The boundary conditions are specified in a rotated coordinate system trano Transformation reference number previously defined by the TRANSFORMATION command SELECT Nodes are to be selected now select nodes Select nodes see Section 5 1 TAGGED Refers to previously selected tagged nodes see the TAG UN TAG commands UNTAGGED Refers to all but the previously selected tagged nodes see the TAG UNTAG commands NOTES The brackets denote optional parameters I e if you do not specify any coordinate system then the global system is used by default SESAM Presel Program version 7 3 0
150. tring may be skipped for a superelement without loads SESAM Presel Program version 7 3 01 OCT 2004 3 27 LWALL NORTH SWALL NORTH LWALL SOUTH FLOOR BASIC SWALL SOUTH second level superelement 10 name is STOREY Figure 3 18 Identifications of superelement occurrences included in superelement 10 STOREY Supernodes are then defined at the bottom and top planes for superelement 10 STOREY BOUNDARY SUPER SUPER SUPER SUPER SUPER SUPER GLOBAL SELECT PLANE 2 PLANE COORDINATE 0 0 0 8 COORDINATE 0 0 0 PLANE 2 PLANE COORDINATE 0 0 3 8 COORDINATE 0 0 0 END Then the top level superelement 100 is created and given its name ASSEMBLY NEW 100 NAME CREATE HOUSE Now when including superelement 10 twice to make the two storeys of the house the location strings of the first level superelements included in 10 are assigned new location strings The current strings are modified by the LOCATION USE command The new location strings are more specific reflecting that the positions of the superelements in the complete model are more specific The first inclusion of 10 is the ground floor GRD is therefore added to the location strings The second inclusion is the first floor 1ST is therefore added to the location strings INCLUD Gl 1 NOPRINT CHECK INCLUDE LOCATION CREATE BASIC PERFORM INCLUDE Ao CK INCLUDE n for the south walls SOUTH S
151. tton under heading Select is merely a consequence of GUI consistency with other SESAM preprocessors and has little relevance for Presel It must be depressed the default condition to allow graphical selection clicking and rubberband of nodes The Set button under heading Select is merely a consequence of GUI consistency with other SESAM preprocessors and has little relevance for Presel Line mode input The upper line presents the last given input SESAM Presel Program version 7 3 01 OCT 2004 3 5 The lower line includes the prompt for input and data entered in line mode You may paste Ctrl V text into the line mode input area e Cursor position feedback The node number triplet of the node at or close to the cursor position is listed here If more than one node is within the tolerance of the cursor position then the triplets of all these nodes will be listed Note While entering a command by the keyboard it is not possible to click buttons or commands until hitting the Return key or deleting all data typed This involves that if you inadvertently have entered a space character which you may overlook as you cannot see it clicking com mands as well as selecting nodes and elements by clicking will not work Use the backspace to delete the space character s 3 2 Assemble Superelements This section explains how to assemble superelements to form the complete model The basic procedure is first
152. tween the two points are selected All nodes on the infinite line are selected The point is the subsequently given node The point is defined by the subsequently given cartesian coor dinates Coordinates referring to the cartesian system of the superele ment The point is defined by the subsequently given coordinates re ferring to the cylindrical coordinate system coord name This option will only appear if the command USE COORDINATE SYSTEM has previously been given within the current selec tion sequence Coordinates referring to the cylindrical coordinate system co ord name All nodes in an infinite plane defined by two or three points are selected The tolerance or thickness of the plane is defined by the SET COORDINATE TOLERANCE command The plane is defined by three points see Figure 5 1 The plane is defined by two points see Figure 5 1 Presel 5 6 VOLUME SET setname ALL END SESAM 01 OCT 2004 Program version 7 3 All nodes inside a box shaped volume are selected see Figure SL Select all nodes of a given set Name of a previously defined set Select all nodes of the current superelement Stop selecting more nodes Note Use the command END to conclude a node selection sequence Do not use the command as that will involve termination of the current command with no nodes selected 5 2 Detailed Description of Commands The input commands are described in the following The command
153. ult choices that are accepted by either e Hitting the Return key Presel SESAM 3 4 01 OCT 2004 Program version 7 3 e Clicking either of the Direct access buttons semicolon and double slash The former accepts all subsequent default values see Section 4 1 2 while the latter accepts a single default value i e the one shown in slanted font Shortcut commands These provide one click access to commonly used compound commands A Shortcut command is logged as its equivalent full standard commands Direct access buttons These buttons are accessible at any time I e when you are in the middle of a command by clicking a command or a shortcut command or by typing a line mode command you may rotate and zoom to get a better view The buttons and are logged with the default values they accept The button is logged as is The other buttons are not logged see Section 4 1 3 on logging commands The Pan button allows panning shifting the display Click the button then press and hold the LMB within the Graphic display area and a bounding box of the displayed model appears Move the mouse and release the LMB and the model will be displayed in its new position The Rotate button allows interactive rotation of the display Click the button then press and hold the LMB within the Graphic display area and a bounding box of the displayed model appears Move the mouse up and down to rotate the m
154. uperelements A superelement is basically a finite element FE model of a part of the complete structure The SESAM preprocessors Preframe for frame modelling and Prefem for general FE modelling are used for creating first level superelements i e part models com prised of finite elements like beams shells etc adjoined in nodes Presel is used to put these parts together to form superelement assemblies First level superelements are typ ically assembled to form second level superelement assemblies these are in turn assembled to form third level superelement assemblies and so on until the complete model the top level superelement assembly is formed Note that a superelement assembly is referred to as a superelement when itself is included in an assembly Superelements on levels higher than 1 i e superelements created by Presel rather than by Pre frame Prefem are often referred to as higher level superelements A superelement hierarchy showing the assembly process from bottom to top can be sketched as illustrated for the two examples in Figure 1 1 An unlimited number of superelements can be included in a superelement assembly Furthermore there is no limit to the number of levels of a superelement hierarchy A superelement model may be used for linear structural analysis using Sestra or hydrodynamic analysis wave loading and motion of frame structures using Wajac and of general structures using Wadam First level superelem
155. ven However you will normally not know this The ISO 8632 3 Computer Graphics Metafile CGM plot format binary encod ing File extension is CGM This format is convenient for including plots in re ports see more information on this in Section 4 1 4 A Hewlett Packard plot format File extension is HPG2 A Hewlett Packard plot format File extension is HP70 The PostScript plot format File extension is PS A plot format of the SESAM system This is the default format on most computers File extension is PLO The SESAM auxiliary program Pltenv is required to repro duce the plot on paper A plot file will not be created rather the plot will be sent directly to an on line print er Set the page orientation This command is presently redundant as portrait is the only choice Portrait orientation Set the plot page size All sizes are not available for all plot formats For SESAM NEUTRAL this setting is irrelevant as the page size is set within the PLOT com mand Give this command after the SET PLOT FILE FORMAT commands and prior to the PLOT command European standard page sizes paper formats See explanation for the PLOT com mand A4 is the default choice For PostScript and HPGL 2 the size specification in the PLOT command is dummy It will not change the plot size The specification has not been removed to ensure compatibility with old input files For SESAM NEUTRAL format the SET PLOT PAGE SIZE has no effect as
156. ves to force it into being SUPERL beta Linear dependency factor SESAM Presel Program version 7 3 01 OCT 2004 5 49 LINEAR DEPENDENCY TWO NODE DEPENDENCY TWO NODE DEPENDENCY as dep node triplet indep node 1 triplet FORCE INTO SUPER indep nodel triplet indep node2 triplet beta FORCE INTO SUPER indep node2 triplet PURPOSE The command defines linear dependency for a node on two other nodes All d o f s of the dependent node are dependent of the corresponding d o f s of the first independent node by the factor beta and the second independent node by the factor 1 beta See also Section 3 6 Note that alternatively to defining the independent node as super prior to this command it may be made super within this command by the FORCE INTO SUPER option Using this option for a node already being super has no consequence PARAMETERS dep node triplet Node number triplet supno index nodeno of the dependent node indep nodel triplet Node number triplet supno index nodeno of the first independent node FORCE INTO SUPER Using this option implies that the d o f s of the independent nodes are forced into SUPERL if they are not SUPER or SUPERL already indep node2 triplet Node number triplet supno index nodeno of the second independent node beta Linear dependency factor Presel SESAM 5 50 01 OCT 2004 Program version 7 3 LOAD ASSEMBLY LO
157. viously defined for the included superelements but nodal forces may also be defined Once a higher level superelement is included in yet a higher level superelement it can no longer be modified in any way for example by including more superelements or defining boundary conditions and loads The top highest level superelement is complete when the whole model to be analysed has been formed including all its loads and boundary conditions There is no limit to at which level this top level is The top level number is simply a result of the hierarchical assembling of superelements from bottom to top The final task of Presel is to produce write the Input Interface Files T FEM the T files for all higher level superelements that has been created Presel 2 2 SESAM 01 OCT 2004 Program version 7 3 2 2 Short Description of Commands A short description of each main command in Presel is given below ASSEMBLY BOUNDARY CHANGE COORDINATE SYSTEM DEFINE DISPLAY HELP INCLUDE LABEL LINEAR DEPENDENCY LOAD NAME OPTIMIZE PLOT PRINT READ creates a new higher level superelement or opens an old one This is then the current superelement The current superele ment is displayed by the DISPLAY command and superele ments may be included into it using the INCLUDE command defines boundary conditions for the current superelement changes loads transformations and linear dependencies defines a coordinate sys
158. wave loads the group of loads method reduces the amount of input Section 3 3 4 explains this e LOAD ASSEMBLY This is an even more advanced method for combining loads Section 3 4 explains this 3 3 1 Why Combine Loads Since superelements may be used repeatedly to establish the complete model a certain superelement number may be found in several different locations in the model each location termed a superelement occurrence and identified by an index number These different superelement occurrences will typically be subjected to different loads For example for a model submerged in water two occurrences of the same superelement will due to their different positions be subjected to different water pressures To account for this one load ing condition is represented by two different load cases when modelling the superelement in Prefem or Pre frame These two load cases then need to be put together i e combined when the superelements are assembled Combining loads is in effect assigning the proper load to the proper superelement occurrence In this proc ess the different superelement occurrences need to be identified This is done by referring to two numbers the superelement number and the superelement index Section 3 2 4 explains the superelement index Note Only the load combinations made for the top level superelement are the loads analysed in Ses tra and available for postprocessing Le a load case that not directly or t
159. y conditions A cylindrical coordinate system is defined by three points its origin a point defining its z axis and a point defining its 0 plane which determines the r axis See Figure 5 2 The three points may be defined by giving coordinates in the cartesian system of the superelement or nodes may be referred to PARAMETERS coord name User given name of the coordinate system CYLINDRICAL A cylindrical coordinate system is defined COORDINATE Define point by giving its coordinates XYZ Coordinates in the superelement s cartesian system NODE Refer to nodes supno index nodeno The node number triplet gt o 0 plane a Ss 9 0 p r cartesian coordinate system of current superelement cylindrical coordinate system Figure 5 2 Cylindrical and spherical coordinate systems SESAM Presel Program version 7 3 01 OCT 2004 5 15 NOTES Note that the coordinate system is only defined for and therefore available to the current superelement Coordinate systems defined are printed by the PRINT TRANSFORMATION command The coordinate system name coord name is not given in the printout but rather an internally assigned number Presel SESAM 5 16 01 OCT 2004 Program version 7 3 DEFINE SET intersection with SUBTRACT BY NODE select nodes DEFINE SET setname UNION WITH END PURPOSE The command defines a set of nodes that may be referred to in commands where selecting nodes

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