從nastran到adams的產(chǎn)生柔體幾種方法[精品ppt課件]

1、Table of ContentsPurpose of MSC.Nastran/Adams Flex Interface Features SupportedUsers InterfaceOutput for MSC.AdamsMSC.Adams UnitsMSC.Nastran/Adams Interface ExamplesExample 1Component as a superelementExample 2Component as residual structure onlyExample 3Component Restarting from SOL 106 to SOL 103G

2、uidelines and LimitationsPurpose of MSC.Nastran/Adams Flex InterfaceIncorporates reduced flexible body component dynamics from MSC.Nastran into MSC.Adams FlexFor performing system flexible body analysisincluding large rigid body motionsTypical Applications:Elasto-kinematic analysis of vehicular susp

3、ensionsEngine crankshaft-drive train interactionAircraft landing conditionsSatellite panel deploymentPurpose of MSC.Nastran/Adams Flex Interface (cont.)Prior to MSC.Nastran 2004, this type of coupling is a two steps processGenerates an output2 file from MSC.Nastran using an dmap alterConverts this o

4、utput2 file into an MSC.Adams Modal Neutral file (MNF file) using OUT2MNF This file is then readable by MSC.Adams FlexIn 2004, you can generate the MNF file directly from MSC.NastranFeatures SupportedThe component can be a superelement The exterior points are the attachment pointsSupports both main

5、bulk and part superelementsThe component can be residual structureUse ASET/ASETi to define attachment pointsSupports the use of statsub for prestiffening with small deflection in SOL 103Supports large displacement with preloadRun SOL 106 with preload and save databaseRestart in SOL 103 using “param,

6、nmloop,x”Users InterfaceOnly two new commands/entries are requiredCase Control command to generate MNF fileADAMSMNF FLEXBODY=YESBulk Data Entry to specify units used by ADAMS/FlexDTI,UNITS,1,mass_unit,force_unit,length_unit,time_unite.g.,DTI,UNITS,1,KG,N,M,SECAdditional features will be shown in the

7、 example sectionsUsers Interface (cont.)Full ADAMSMNF Case Control commandMost commonly used optionsOutput for MSC.AdamsThe following output are generated for MSC.Adams:Modal stiffnessModal massModal loadDiagonal matrix of a-set unit boundary displacementPhysical mass matrixStress shapeStrain shapeM

8、SC.Adams UnitsMSC.Adams is not a unitless codeParam,wtmass,x is used in MSC.Nastran to scale weight/mass units, but is ignored in Adams/FlexCorrect set of units must be specified on the DTI,UNIT,1,. entryExample:If the model are using the following unitsMass:gramsForce:NLength:metersTime:secondsMSC.

9、Adams Units (cont.)Example (cont.):The corresponding scale factor on wtmass is .001,but the following DTI entry must be usedDTI,UNITS,1,gram,n,m,sA list of acceptable units for MSC.Adams is shown below:MSC.Nastran/Adams Interface ExamplesThe simple plate model to the right is used to illustrate 3 se

10、parate salient features of the MSC.Nastran/Adams interface.The first example is for a flexible body component as a superelement.The second example is for a flexible body component using residual structure onlyThe third example is to preload the structure in SOL 106 and restart into SOL 103 to genere

11、ate the flexible body component Example 1Component as a superelementModel the whole structure as a superelement with grid points 1, 11, 111, and 121 as boundary points (exterior points)This is done by the usual SESET entriesThese boundary points also become attachment points in MSC.AdamsDefine the S

12、POINTs and SEQSETs for component modesDefine the units for MSC.AdamsDTI,UNITS,1,mass_unit,force_unit,length_unit,time_unitExample 1Component as a superelement (cont.)Request mass invariants for export to MSC.AdamsThis is done by the param,grdpnt,xThe GPWG module will be executed twiceonce for the re

13、gular mass matrix for MSC.Nastran and once for the MSC.Adams.The mass matrix is always calculated about the origin of the basic coordinate system for MSC.AdamsRequest MNF file for MSC.AdamsThis is done by the “ADAMSMNF flexbody=yes” Case Control calloutUse PLOTEL elements to create reduced geometry

14、for MSC.Adams displayThis is done by the PSETID=x option on the ADAMSMNF Case Control command.The PSETID points to a set ID referenced in the OUTPUT(PLOT) sectionExample 1Component as a superelement (cont.)Input FileSOL 103CEND$TITLE= SIMPLE PLATE MODEL 10 X 10 ELEMENTS$ADAMSMNF flexbody=yes, psetid

15、=100$METHOD=300$RESVEC = COMPONENT$ Set to define component shapes$OUTPUT(PLOT)SET 100 = 10001 THRU 10010$BEGIN BULK$ ADAMS REQUIRES following DTI$DTI,UNITS,1,KG,N,M,SEC$ Turn on gridpoint weight generator$PARAM,GRDPNT,0$EIGR 300 LAN 10$SESET,200,2,THRU,10SESET,200,12,THRU,110SESET,200,112,THRU,120$

16、SPOINT,80001,THRU,80018SEQSET1,200,0,80001,THRU,80018$PLOTEL,10001,1,12PLOTEL,10002,12,121PLOTEL,10003,121,111PLOTEL,10004,111,1PLOTEL,10006,2,10PLOTEL,10007,22,110PLOTEL,10008,120,112PLOTEL,10009,12,100$ SEELT to put element 1003 and 1004 into SE 200$SEELT2001000310004$ Get model data and load data

17、$include model1.dat$ENDDATAExample 1Component as a superelement (cont.)Abridged OutputExample 1Component as a superelement (cont.) Abridged Output (cont.)Example 2Component as residual structure onlyModel the whole structure as residual with grid points 1, 11, 111, and 121 as attachment points to MS

18、C.AdamsThis is done by specifying the boundary grids with the ASET entriesDefine the SPOINTs and QSETs for component modesDefine the units for MSC.AdamsDTI,UNITS,1,mass_unit,force_unit,length_unit,time_unitRequest mass invariants for export to MSC.AdamsThis is done by the param,grdpnt,xThe GPWG modu

19、le will be executed twiceonce for the regular mass matrix for MSC.Nastran and once for the MSC.Adams.The mass matrix is always calculated about the origin of the basic coordinate system for MSC.AdamsExample 2Component as residual structure only (cont.)Request MNF file for MSC.AdamsThis is done by th

20、e “ADAMSMNF flexbody=yes” Case Control calloutUse PLOTEL elements to create reduced geometry for MSC.Adams displayThis is done by the PSETID=x option on the ADAMSMNF Case Control command.The PSETID points to a set ID referenced in the OUTPUT(PLOT) sectionExport grid point stress/strain shapes to the

21、 MNF fileThis is done with the stress, gpstress, strain, and gpstrain commandPlot option can be used to reduce the amount of outputAn OUTPUT(POST) along with the surface definition for the normal gpstress/gpstrain type requestExample 2Component as residual structure only (cont.)$SOL 103CEND$TITLE= w

22、ithout superelement $ADAMSMNF flexbody=yes, psetid=7772$METHOD=300$RESVEC = COMPONENT$STRESS(PLOT)=ALLSTRAIN(PLOT)=ALLGPSTRESS(PLOT) = ALLGPSTRAIN(PLOT) = ALL$OUTPUT(PLOT)SET 7772 = 10001 THRU 10010$OUTPUT(POST)SET 9998 = ALLSURFACE 9998 SET 9998 fibre z1 NORMAL X3$BEGIN BULK$ ADAMS REQUIRES followi

23、ng DTI$DTI,UNITS,1,KG,N,M,SEC$ Turn on gridpoint weight generator$PARAM,GRDPNT,0$ Default value - ADAMS must use the above DTI,UNITS$PARAM,WTMASS,1.0$EIGR 300 LAN 10$ASET1,123456,1,11,111,121$SPOINT,80001,THRU,80018QSET1,0,80001,THRU,80018$PLOTEL,10001,1,12PLOTEL,10002,12,121PLOTEL,10003,121,111PLOT

24、EL,10004,111,1PLOTEL,10006,2,10PLOTEL,10007,22,110PLOTEL,10008,120,112PLOTEL,10009,12,100$include model1.dat$ENDDATAInput FileAttachment PointsExample 2Component as residual structure only (cont.) Abridged OutputExample 2Component as residual structure only (cont.) Abridged Output (cont.)Example 3Co

25、mponent Restarting from SOL 106 to SOL 103 Preload the structure in SOL 106 with a distributed tensile loads at the end and restart to calculate modes in SOL 103This is a two steps processFor the SOL 106 cold start run Perform normal SOL 106 runincluding turning on large displacement if desired (par

26、am,lgdisp,1)Define the SPOINTs Save the database (scr=no)SPCF(PLOT)=all to form the total reactive preload in SOL 103For the the SOL 103 restart runDefine the QSETsParam,nmloop,x where x is the loopid to restart fromExample 3Component Restarting from SOL 106 to SOL 103 (cont.)For the the SOL 103 res

27、tart run (cont.)Define the units for MSC.AdamsDTI,UNITS,1,mass_unit,force_unit,length_unit,time_unitRequest mass invariants for export to MSC.AdamsThis is done by the param,grdpnt,xThe GPWG module will be executed twiceonce for the regular mass matrix for MSC.Nastran and once for the MSC.Adams.The m

28、ass matrix is always calculated about the origin of the basic coordinate system for MSC.AdamsRequest MNF file for MSC.AdamsThis is done by the “ADAMSMNF flexbody=yes” Case Control calloutUse PLOTEL elements to create reduced geometry for MSC.Adams displayThis is done by the PSETID=x option on the AD

29、AMSMNF Case Control command.The PSETID points to a set ID referenced in the OUTPUT(PLOT) sectionExample 3Component Restarting from SOL 106 to SOL 103 (cont.)$ The data base must be saved for this run therefore SCR=NO requiredSOL 106CEND$TITLE= SIMPLE PLATE MODEL 10 X 10 ELEMENTS$NLSTRESS = ALL$SUBCA

30、SE 200LABEL= static stiffining load in plane of plate for preloadSPCF(PLOT) = ALL $ Generate forces of constraintSPC = 100 $ LOAD=100$NLPARM = 1$BEGIN BULK$PARAM,LGDISP,1NLPARM,1,4,UPW,YES$ Default value - ADAMS must use the DTI,UNITS$PARAM,WTMASS,1.0$ Add in plate tensioning follower load$FORCE1 10

31、0 111 3000. 1 111FORCE1 100 112 6000. 2 112FORCE1 100 113 6000. 3 113 .FORCE1 100 120 6000. 10 120FORCE1 100 121 3000. 11 121$FORCE1 100 1 3000. 111 1FORCE1 100 2 6000. 112 2FORCE1 100 3 6000. 113 3 .FORCE1 100 10 6000. 120 10FORCE1 100 11 3000. 121 11$ static support set for preload$ SPC1 100 123 1

32、SPC1 100 13 11SPC1 100 3 111$SPOINT,80001,THRU,80019$include model1.dat$ENDDATACold start run Example 3Component Restarting from SOL 106 to SOL 103 (cont.)$ Get the data base for the nonlinear run$ASSIGN run1=adams3a.MASTERrestart logical=run1$SOL 103CEND$TITLE= SIMPLE PLATE MODEL 10 X 10 ELEMENTS$A

33、DAMSMNF flexbody=yes, psetid=7772$METHOD=300$RESVEC = COMPONENT$PARAM,NMLOOP,4$SUBCASE 2LABEL=Sol 106 preloadload=100$ Set to define component shapes$OUTPUT(PLOT)SET 7772 = 10001 THRU 10010$BEGIN BULK$DTI,UNITS,1,KG,N,M,SEC$PARAM,GRDPNT,0$ EIGR 300 LAN 10$ $ASET1,123456,1,11,111,121$QSET1,0,80001,THRU,80019$PLOTEL,10001,1,12PLOTEL,10002,12,121PLOTEL,10003,121,111PLOTEL,10004,111,1PLOTEL,10006,2,10PLOTEL,10007,22,110PLOTEL,10008,120,112PLOTEL,10