Nastran梁單元應力輸出

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

2、3AlternateFormat臼ndExample:CBAREIDP1DGAGBGOOFFTW1AW2AW3AW1BW2BW3BCBAR23976105GOG5J3CBAR單元屬性卡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=訶十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篤T,忙HAN篤T；汨OX；FAR*,“CRO5S：H篤“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梁單元應力輸出一維梁單元中的內力或應力可以通過單元力或單元應力輸出（如FORCE或者ELFORCE）來進行輸出，并且梁單元只輸出應力恢復點的應力。如果梁截面是標準庫中的截面（PBARL，PBEAML定義的截面），則應力恢復點已經(jīng)由程序根據(jù)不同的截面形狀進行定義，不需要用戶定義。如果是自己定義的梁截面（PBAR,PBEAM定義的截面），則用戶必須自行定義應力恢復點（屬性卡片中的C1,C2、D1,D2、E1,E2、F1,F2）。此時beamelements的應力需要選擇recoverypointonthebeamcrosssection，然后在stressrecoverypointC/

17、D/E/F-Element-Nodal中可以看到對應的應力分析結果。2.1.CBAR梁單元的單元力和應力下圖是CBAR梁單元力（elementforce）的正方向。real或者complex形式（取決于輸出格式）的單元力的輸出包括下面幾項：PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).GridPointGAFigure8-11CBARElementGeometrywithOffsetsPBARSimpleBeamPropertyDufinusthepropertiesof-asimplebe

18、amelement(匚BARentry).yM1a,M1b,M2a和M2b是分別在兩個參考平面中，兩個端點處的彎矩。V1和V2是在兩個參考平面中的剪力，F(xiàn)x是平均的軸向力，T是繞x軸的扭矩。輸出中可以要求輸出CBAR單元下面的real形式單元應力(elementstress)：平均軸向應力(averageaxialstress)：axialstress由在兩個端點A、B處橫截面上的4個應力恢復點的彎矩引起的張性應力(extensionalstressduetobending)：SA1、SA2、SA3、SA4，SB1、SB2、SB3、SB4。僅當用戶在PBAR卡片中輸入了應力恢復點，才計算該彎曲

19、應力。兩個端點A、B處的最大和最小的張性應力(maximumandminimumextensionalstressatbothends)：SA-MAX、SA-MIN、SB-MAX、SB-MIN。該最大和最小的張性應力是由每端軸向應力和彎曲張性應力的合成。拉伸安全系數(shù)和壓縮安全系數(shù)(Marginsofsafetyintensionandcompression)。僅當用戶在MAT1卡片中輸入了應力極限(stresslimits)時，才計算該安全系數(shù)。拉伸應力為正值，壓縮應力為負值。只有平均軸向應力和彎曲張性應力可以是復數(shù)應力(complexstrss)。對于梁單元的應力輸出，patran04中有以

20、下選項：軸向(barstresses,axial)(atcenter)barstresses，bendingposition(AtpointCDEF)最大、最小合成(atcenter)Maxshear在Hyperview后處理Nastran的CBAR單元時，梁單元CBAR中的單元力和單元應力的輸出如下：elementIDSA1SA2SA3SA4AXIALSTRESSSA-MAXSA-MINM.S.-T(safetymargintension)SB1SB2SB3SB4SB-MAXSB-MINM.S.-C(safetymarginCompression)其中：A,B表示梁的兩個端面。1-4是用戶指

21、定的用來計算應力的截面上的四個點。SA1-SA4，SB1-SB4是僅由純彎曲所引起的正應力(NormalStressDuetoBendingOnly)，AXIALSTRESS是僅有軸向載荷所引起的正應力(NormalStressDuetoAxialLoadOnly)，SA-MAX，SA-MIN，SB-MAX，SB-MIN是彎曲與軸向載荷組合情況下的兩個端面的最大、最小正應力(CombinedAxialandBendingStress)。M.S.-T是拉伸安全系數(shù)，M.S.-C是壓縮安全系數(shù)。2.2.CBEAM梁單元的單元力和應力EndA(0,0f0)NeutralAxis亂offsstGrid

22、PointGA3勿淪1珞紐勿/?NonstructuralMassCenterofGravityShearCenterEndR(陽0.0)offsetGridPointGBYmb|忙IzribFigure8-15CBEAMElementGeometrySystem(Nonp-adaptive)PBARSimpleBeamPropertyDufinusthepropertiesof-asimplebeamelement(匚BARentry).lemYelemxeleinFigure8-17CBEAMInternalElementForcesandMomentsCBEAM單元的應力輸出與CBAR單

23、元有些不同。對于CBAR單元，SAi和SBi列只是彎曲應力，而軸向應力單獨列出。但是對于CBEAM單元，SXC、SXD、SXE和SXF是在CBEAM中橫截面上應力恢復點C、D、E、F處的彎曲應力和軸向應力的組合。在CBEAM的每個端點進行應力恢復，還可以在任何由PBEAM輸入卡片確定的中間位置進行應力恢復。在Hyperview后處理Nastran的CBEAM單元時，梁單元CBEAM中的單元力和單元應力的輸出如下：CBEAMlongCBEAMlongCBEAMlongCBEAMCBEAMCBEAMmarginofsafetytension1marginofsafetystressatstressatstressatpointlongstre