Nastran梁单元应力输出.docx

1、Nastran梁单元应力输出1. Nastran梁单元1.1. CBAR单元卡片Grid Point GAFigure 8-11 CBAR ElemEnt Geometry with OffsetsFigure 8-12 CBAR Element Geometry without OffsetsCBARSimple Beam Element ConnectionDefines a simple beam element.Format:CBAREroPIOGACrBXIX2X3OFFTPAPRW1AW2AW3AW1BW2FJW1R2 3 46 7H 9 10Example:CHAR239730.

2、6】乳26.GOG513Alternate Format and Example：EIDPIDGAGOOFF1PAPBW1AW2AW3AW1BW2BP W3BCBAR23976105GOG513CBAF单元属性卡PBAR Simple Beam PropertyDr fines the properties of a pimple bciur cknicnt K BAR entry .Format:7 H -9 10MID Malerial identi Scat ion number See Remarks 2- /nd 占.(Integer U)A Area u f bar er口號 se

3、ction. ( Real; Dcf aul t (J 0)II 2,112 Areamonientsofinenh. See Figure fi-156. (Real; II 0 0. 12 _0.0,11*12 112:;Default = 0.0)J Tursioniil con slant. See F igure 3 156. (Real: Ocfuuh Ui + A) fur SOL 600 and0.0 fu-r sill ihtr sulutioii 帯門电cncusNSSt unstrucluraJ mas.per unil length. ReulCi, Di. EL Fi

4、 Stress rccocr cDcnicients. iReul: Ekfhuli - 0.0)K1 ? K2 Area lector far shear. See FternEuk 5. (Real or blank)PBARL Simple Beam CrossSection PropertyDefines the 卩 roperties of a simple beam deme (C BAR entry) by cross-sectional dimensions.Format: 23456789 10PBARLP1DMIDGROUPTYPEDIMIDIM；D1M3D1M4DIMSD

5、IM6DIM7DIMSDIM9-etc.-NSMExample:PBARL39614”氐.5.5552r斗Field ContentsDIMIjlcnTYPE= RODTYPt-TUHE-eienn-EtemDIM2TPF=TUAE7DIM 1174*-+ DI加TYPECHANHITYPE=BARH,TFE寸 FTlebanDIM 3TVPE=I1nFigure 8-158TYPWGROUP = MSCBMLO (contnued) l-l. .11E DTYPEr1TYPE=hT21TYPE=iCHAN1HDIMI DIM1TYPE-XHAN2F严C fjLIM31101M21-eiam+

6、1IMDIM4EDIM4* 4D + bi腑.一七mTYPE= BOXVFigure 8-159 Definition of Cross-Section Geometry and Stress Recovery Points forGROUP = WSCBMLCT (continued)TYPE -DBOXpFigure 8-160 Definition of Cross-Section Geometry and Stress Recovery Points for GROUP - MSCBMLCT (continiied)1.2. CBEAM单元卡片z&iemL*-Vma一卜丨Yna Irm

7、a、na I 1End A (0. 0. 0)乱 offsetI r r jf r Section PropertyDefines ihe- properties of a beam element by cross-sectia nnl dime nsdons.Format:(Note: n = number of dimcmions and tn = number ofintcnnediaic Nations)1234567K9I0PBEAMLPIDMIDGROUPTYPEDIM 1( A)DIM2(A)YtG-D(Mn(ANSM(A)SCXUX| 1) XBD1M2H J-etc.-DI

8、Miill)1SSM(1SO(打X(2yXBDIM 1(2)D1M2(2)-etc.-DJMn(2)NSMfm-etc.-SO(m)X(ni)CXBDFMKni)-etc.-DIMnim)USM(m)SO(B)LODIM 1(B)-etc.-D1Mn(B)NSM(B)Example:PBEAVIL鼻921112t14.82.52.6NO0.46.7-122.6YES0.67.S5.623YESFieldConte nteDefault Values11(A)Area nmnicnt of inertia at end A for bendinj in plane 1 about (he neu

9、tral axis. See RcmaTk 10. 4 Real 0.0 kRequire内Area momiciil at inertia al cndl A tor bending in plane 2 aboiil the neutral axis. See Remark 10. 1 Real 0.0)Kequircd0.0. Area produd of incrliLi at rnd &、See Remark10 (Real,but i -i/ur to)J(A)Torsional sliffiiess parameter 皿 end A. See RemarkDefaulr=(j

10、+f計 fbr10. (Real 0.0 but 0,0 if warping is present)SOL 600 ad 0 0 rbr al ether elution sequencesNSM(ANunsimclunil nuss per unit lcnglh al end A. (Real)0.0Ci(A , DigThe y and z liocatians. (i = 1 con-Espouds to y and i = 2 corresponds to z) in elcmeriit ciMrdinatesy = z = 0.0Ei(AK Fi(A)rchtis c to th

11、e sh?ar center (see rhe diagrain fblkiwing the TcnsrJtxi ar end ter stress ciJta rccocr; iRcal)SOStress output request uptiun. See Rcniiirk 9. (C banjcler IYES1 Srtsscs recovered at points fL Di. Ei. and Fi cn lhe ncxi cairiniuiion.YESA，_ Stresses recovered at points wilhlhe same y aid 7. location a

12、s end ALNCT No strcsiio： or forces are recovered.kequired,XXUDiiManci： from cr?d A m the eltmcrii DordinotcKequircd*sylcni divided, by the length of die clcnienll SecFigjre B-1B3 in FLemark HJ.(KeaJ a 0,0)See Remark. 6.A, II.12J11Anta, momcnlii rrinertia, torsional slifTncfiS paiamclcr and nonstruct

13、ural mass tor the cidsSee Reniurk 7.J.NSMsection looted ai x. (Real; J1 00 if warping is present.)Ci Di. F.i, FiThe y and z locations (i = 1 coiTesporids to y and i. 2 tcsrTCippnds lu z) in ekrTwnt courdi nates rchti c to the shar center (see Figure 8-163 in Rennark 10 ) fhr ihc erm驚 swtitfin Incaio

14、d at X- XR The values ore fiber locations for stress chta rcccmry【gno代d for beam pHEknn 此时 beam elements 的应力需要选择 recovery point on the beam cross section, 然后在 stress recovery point C/D/E/F- Eleme nt-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（element force）的正方向。real或者complex形式（取决于输出格式）的单元力的输出

15、包括下面 几项：End aPlane 1Plane 2End b今Grid Point GBGrid Point GAFigure 8-11 CBAR Element Geometry with OffsetsPlane 1 bz %Figure 3-7 CBAR Element ForcesM1a, 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（eleme nt stress）：（1） 平均轴向应力（ average axial stre

16、ss : axial stress（2） 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（exte nsio nal stress due to ben di ng）： 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，才计算该弯曲应力。(3)两个端点 A、B 处的最大和最小的张性应力(maximum and minimum extensional stress at both ends): SA-MAX SA- MIN 、SB-MAX SB-MINo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。(4

17、) 拉伸安全系数和压缩安全系数(Margins of safety in tension and compression。仅当用户在 MAT1卡片中输入了应力 极限(stress limits)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( complex strss)。对于梁单元的应力输出，patran04中有以下选项：(1)轴向(bar stresses ,axiaj (at center)(2)bar stresses bending position( At point C D E F(3)最大、最小合成(at center)(4)

18、Max shear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：eleme nt IDSA1SA2SA3SA4AXIALSTRESSSA-MAXSA-MINM.S.-T (safety margin tension)SB1SB2SB3SB4SB-MAXSB-MINM.S.-C (safety margin Compression)其中：A,B表示梁的两个端面。1-4是用户指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(Normal Stress Due to Ben di ng Only)

19、AXIAL STRESS 仅有轴向载荷所引起的正应力 (Normal Stress Due to Axial Load On ly)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 (Comb ined Axial a ndBending Stress)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Figure 8-15 CBEAM Element Geometry System (Non p-adaptive)Figure 8-17 CBEAM Internal Element F

20、orces and MomentsCBEAM单元的应力输出与CBAF单元有些不同。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：eleme ntIDCBEAM long stress at poi nt C1CBEAM long stress at poi nt D1CBEAM long stress at point E1CBEAM long stress at point F1CBEAM Maximum stress1CBEAM Mi nmum stress1margin of safety tension1margin of safety compressi on1CBEAM long stress a