Nastran梁单元应力输出

1、1.Nastran梁单元l.l.CBAR单元卡片Plane1GridPointGAFigure8-11CBARElementGeometrywithOffsetsGridPointGBPlane1iEndaFigure8-12CBARElementGeometrywithoutOffsetselemCBARSimpleBeamElementConnectionDefinesasimplebeamelement.Format;CBAREIDPIOGAGBXIX2X3OFFTPAPRW1AW2AW3AW1RW2BW3B34567B910Example:CBAR丄39730.6J8.26.GOG5J

2、3AlternateFormat臼ndExample:CBAREIDP1DGAGBGOOFFTW1AW2AW3AW1BW2BW3BCBAR23976105GOG5J3CBAR单元属性卡PBARLSimpleBeamCross-SectionPropertyDefines(hepropertiesofasimplebeamelement(CBARentry)bycross-sectionaldimensions.PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).F&rmat:234JR-9L0PB

3、ARLSimpleBeamCross-SectionPropertyDefines(hepropertiesofasimplebeamelement(CBARentry)bycross-sectionaldimensions.PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).PBARLSimpleBeamCross-SectionPropertyDefines(hepropertiesofasimplebeamelement(CBARentry)bycross-sectionaldimensio

4、ns.PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).MIDMaterisidentificationnumber.SeeRcmarky2.and3.(Iniegcr0)AI,2,12JAreaofbar工匚口応section.Real;Dcfaulr=0.0)Areamomentscfinertia.SeeFigure8-155.(Real;11孑0.0TL2Q.O3II*121121;Dcfault=fl.0)ForsicnalconslantSeeFigure&-156.(Ftcal;D

5、efault=诃十f訂forSOL6Wand0.0fo-rallotherahtionscqu-cuceiiNSMNonructuramas#perunitlength.(RealCi,Di,Ei,FiStressrecovercDcfUciEnts.(Real:Default=O.d)Areaiactarforshear.SeeFtcmiri5.Real-orblankFormat:234567B9I0PBARLPIDMIDGROUPTYPEDIMDIM2D【M3DIM4DIM5DIMSDIM?DIMEDIM9-etc.-NSMExample:PBARL396I.5.52Fie

6、ldContentsP1DPropertyidentilicaticnnumber.(Integer0)MIDMaterialidentilkaiionnumber.(Integer0)GROUPCross-sectiongroup.SeeRemarks6and8.(Character;Default=(iMSCBML0T1)TYPECross*sectiontype.SeeRemarks6.and8.andFigure8-157.Character:ROD：“TUBE*；“TUBE2笃T,忙HAN笃T；汨OX；FAR*,“CRO5S：H笃“TV,IP；XHANlZ,“CHAN2；T2：“HE

7、XA”，“HAT；“HAT1M,“DBCOTibrGROUP=4LMSCBML0)DIMiCross*sectionaldimensions.(Real0.0forGROUP=“M5CBML(T)NSMNonstrucmralmassperunitlength.NSMisspecifiedafterthelastDIMi.(Default=0.0)Figure6-15ZDefinitionofCnosarSectonGeametardStressRecoveryPointsforGROUP=HMSCBMLDPBARSimpleBeamPropertyDufinusthepropertiesof

8、-asimplebeamelement(匚BARentry).TPE=h,TUBE!,TYPE=HTUBErTYPECHAND|M3XddmTYPE=-BOXnDeternEYPEhROIT-LTYPETFigure8- DefinitionofCross-SectionGeometryandStressRecoveryPointsforGROUPMSCBMLO(continued)PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).1亡kmc-elaoM2TYPEBAR1DIMITPE=/XBD

9、IM1(Ln)-etc.-NSM(m)SO(BinDIM1(B)DIM2(B)-etc.-DIMn(BNSM(B)Example:PBEAML9921T】2M.S2.52.6NO.22.6YESO.G6u7.B5.62.3YESFieldContentsDefaultValues11(A)AreamomentofincrtiaatendAforbendinginplane1abouttheneutralaxis.SeeRemark10.(Real00Required12(A)AreamomentofinertiaatendAforbcndiniginplane2aboutthe

10、neutralaxis.SeeRemark10.(Real0.0)Required112(A)0.0.AreaproductofinertiaatendA.SeeRemark10.(FtcaLbut/-/2-/!2)2o)J(A)ToisidJialstiffnessparameteratend.A.SeeRemark0兔111(=+気+A)for10.(Real0.0but0.Cifwarpingispresent)SOLMOand.0.0forallothersaluticmsoquenresNSM(A)Noastructunimassperunitlength,atendA.(Real!

11、0.0Ci(A|.Di(A、TheyandzlocaTions(i=1canrcspondstoyand.i=2correspondstoz)inelementcoordinatesy=1=0.0Ei(A),Fi0.0)SeeRemark6.A,l.12,112,Area,momentsofinertia,torsionalstiffnessparameter,andnDnstructura.torthecrossSeeRemark7.J,NSMsectionlocatedatx.(Real;J0.0ifwarpingispresent-Ci,Di,EinFiTheyandzlocaTions

12、(i=1canrcspondstoyand.i=2contpuiiLhLuz)inlnint仁口幹ixli口Elc西relativetotheshearcenter(呂eeFigure8=163inRemark-10.)forrhecrossectionlocatedatX-XR.Thevaluesarcfiberlocationsforstressdatarecovery.Ign-orcdforbeamp-tlcmcnts.(Real)PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).JTYP

13、E=E,RODBPTYPE=C,TUBE2PPdemTYPEs-FTYPE=-CHAN,PPBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).TYPE=C,TUBE,:,DIM4DIM3TYPE=MCRO5SSPPBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).TYPE=*BAR1BDl2DIW4DIM1TYPEaz-H-TYPE*疋“TYPE-CHANa1-PBARSimpleBeamProper

14、tyDufinusthepropertiesof-asimplebeamelement(匚BARentry).DIM4FTYPE-Tr10.5DIMIlekm0.5DMITYPE-Llir,TYPE=LICHAN1,rPBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).丄ItemtfcmTYPE=E,T2TYPEsBOXFTYPE寸HAT”IMSDMTYPE=*HAT13PTYPEE,HEXA1PDIMSPBARSimpleBeamPropertyDufinusthepropertiesof-as

15、implebeamelement(匚BARentry).DIMSDIM7IM9DIMWTYPE=JDBOXTDIM7Figure8-164DefinitionofCrts-SectioriGeometryandStressRecoveryPoinlsforGROUP=MSCBML0IM2IM2PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).2.N

16、astran梁单元应力输出一维梁单元中的内力或应力可以通过单元力或单元应力输出（如FORCE或者ELFORCE）来进行输出，并且梁单元只输出应力恢复点的应力。如果梁截面是标准库中的截面（PBARL，PBEAML定义的截面），则应力恢复点已经由程序根据不同的截面形状进行定义，不需要用户定义。如果是自己定义的梁截面（PBAR,PBEAM定义的截面），则用户必须自行定义应力恢复点（属性卡片中的C1,C2、D1,D2、E1,E2、F1,F2）。此时beamelements的应力需要选择recoverypointonthebeamcrosssection，然后在stressrecoverypointC/

17、D/E/F-Element-Nodal中可以看到对应的应力分析结果。2.1.CBAR梁单元的单元力和应力下图是CBAR梁单元力（elementforce）的正方向。real或者complex形式（取决于输出格式）的单元力的输出包括下面几项：PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).GridPointGAFigure8-11CBARElementGeometrywithOffsetsPBARSimpleBeamPropertyDufinusthepropertiesof-asimplebe

18、amelement(匚BARentry).yM1a,M1b,M2a和M2b是分别在两个参考平面中，两个端点处的弯矩。V1和V2是在两个参考平面中的剪力，Fx是平均的轴向力，T是绕x轴的扭矩。输出中可以要求输出CBAR单元下面的real形式单元应力(elementstress)：平均轴向应力(averageaxialstress)：axialstress由在两个端点A、B处横截面上的4个应力恢复点的弯矩引起的张性应力(extensionalstressduetobending)：SA1、SA2、SA3、SA4，SB1、SB2、SB3、SB4。仅当用户在PBAR卡片中输入了应力恢复点，才计算该弯曲

19、应力。两个端点A、B处的最大和最小的张性应力(maximumandminimumextensionalstressatbothends)：SA-MAX、SA-MIN、SB-MAX、SB-MIN。该最大和最小的张性应力是由每端轴向应力和弯曲张性应力的合成。拉伸安全系数和压缩安全系数(Marginsofsafetyintensionandcompression)。仅当用户在MAT1卡片中输入了应力极限(stresslimits)时，才计算该安全系数。拉伸应力为正值，压缩应力为负值。只有平均轴向应力和弯曲张性应力可以是复数应力(complexstrss)。对于梁单元的应力输出，patran04中有以

20、下选项：轴向(barstresses,axial)(atcenter)barstresses，bendingposition(AtpointCDEF)最大、最小合成(atcenter)Maxshear在Hyperview后处理Nastran的CBAR单元时，梁单元CBAR中的单元力和单元应力的输出如下：elementIDSA1SA2SA3SA4AXIALSTRESSSA-MAXSA-MINM.S.-T(safetymargintension)SB1SB2SB3SB4SB-MAXSB-MINM.S.-C(safetymarginCompression)其中：A,B表示梁的两个端面。1-4是用户指

21、定的用来计算应力的截面上的四个点。SA1-SA4，SB1-SB4是仅由纯弯曲所引起的正应力(NormalStressDuetoBendingOnly)，AXIALSTRESS是仅有轴向载荷所引起的正应力(NormalStressDuetoAxialLoadOnly)，SA-MAX，SA-MIN，SB-MAX，SB-MIN是弯曲与轴向载荷组合情况下的两个端面的最大、最小正应力(CombinedAxialandBendingStress)。M.S.-T是拉伸安全系数，M.S.-C是压缩安全系数。2.2.CBEAM梁单元的单元力和应力EndA(0,0f0)NeutralAxis乱offsstGrid

22、PointGA3勿沦1珞紐勿/?NonstructuralMassCenterofGravityShearCenterEndR(阳0.0)offsetGridPointGBYmb|忙IzribFigure8-15CBEAMElementGeometrySystem(Nonp-adaptive)PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).lemYelemxeleinFigure8-17CBEAMInternalElementForcesandMomentsCBEAM单元的应力输出与CBAR单

23、元有些不同。对于CBAR单元，SAi和SBi列只是弯曲应力，而轴向应力单独列出。但是对于CBEAM单元，SXC、SXD、SXE和SXF是在CBEAM中横截面上应力恢复点C、D、E、F处的弯曲应力和轴向应力的组合。在CBEAM的每个端点进行应力恢复，还可以在任何由PBEAM输入卡片确定的中间位置进行应力恢复。在Hyperview后处理Nastran的CBEAM单元时，梁单元CBEAM中的单元力和单元应力的输出如下：CBEAMlongCBEAMlongCBEAMlongCBEAMCBEAMCBEAMmarginofsafetytension1marginofsafetystressatstressatstressatpointlongstre