[转帖]ANSYS柱子稳定分析算例

AaronSpark

<P>! ANSYS柱子稳定分析算例<BR>! 要点：预应力，特征值屈曲，添加初始缺陷，几何非线性分析<BR>finish<BR>/CLEAR<BR>/UNITS,SI <BR>/PREP7 <BR>!* <BR>FORCE=100<BR>OFFSET=0.1 !初始缺陷为0.1 <BR>! 建立模型<BR>ET,1,BEAM4 <BR>ET,2,LINK10 <BR>R,1,0.1*0.12,0.12*0.1**3/12,0.1*0.12**3/12,0.12,0.1, , <BR>R,2,0.002*0.002,2e-3, !预应力 <BR>MPTEMP,1,0 <BR>MPDATA,EX,1,,200e9 <BR>MPDATA,PRXY,1,,0.27 <BR>MPDATA,DENS,1,,7800 <BR>k,1,<BR>k,2,0,0,5 <BR>k,3,0,0,-5<BR>k,11,0.2,0,0<BR>k,12,-0.2,0,0 <BR>k,13,0,0.2 <BR>k,15,0,-0.2 <BR>l,1,2 <BR>l,1,3 <BR>l,1,11 <BR>l,1,12 <BR>l,1,13 <BR>l,1,15 <BR>l,2,11 <BR>l,2,12 <BR>l,2,13 <BR>l,2,15 <BR>l,3,11 <BR>l,3,12 <BR>l,3,13 <BR>l,3,15 <BR>lsel,,,,1,6 <BR>latt,1,1,1 <BR>ALLSEL,ALL <BR>lsel,,,,7,14<BR>latt,1,2,2 <BR>ALLSEL,ALL <BR>lsel,,,,1,6 <BR>LESIZE,all,0.3, , , , , , ,1 <BR>lsel,,,,7,14<BR>LESIZE,all, , ,1 , , , , ,1 <BR>ALLSEL,ALL <BR>LMESH,ALL<BR>FINISH <BR>/ESHAPE,1.0 <BR>!* <BR>! 求解特征值屈曲荷载<BR>*DO,I,1,100<BR>FINISH<BR>/SOLU <BR>DK,3, , , ,0,UX,UY,UZ, , ,ROTZ , <BR>DK,2, , , ,0,UX,UY, , , , , <BR>FK,2,FZ,-FORCE <BR>ANTYPE,0<BR>!设定时间步 <BR>TIME,1 <BR>AUTOTS,0 <BR>NSUBST,1, , ,1 <BR>!NLGEOM,1 <BR>SSTIF,ON </P>
<P>SOLVE<BR>FINISH<BR>/SOLU <BR>ANTYPE,BUCKLE ! Buckling analysis<BR>BUCOPT,LANB,1 ! Use Block Lanczos solution method, extract 1 mode<BR>MXPAND,1 ! Expand 1 mode shape<BR>PSTRES,ON ! INCLUDE PRESTRESS EFFECTS<BR>SOLVE<BR>FINISH<BR>*GET,FREQ1,MODE,1,FREQ<BR>*IF,FREQ1,LT,0.01,THEN<BR>FREQ1=0.01<BR>*ENDIF<BR>*IF,ABS(FREQ1-1),LT,0.01,THEN !如果频率误差小于1%<BR>*EXIT<BR>*ENDIF<BR>FORCE=FORCE*FREQ1<BR>*ENDDO<BR>! 添加初始缺陷<BR>FINISH<BR>/POST1 <BR>SET,FIRST <BR>NSORT,U,SUM <BR>*GET,DMAX,SORT, ,MAX<BR>!* <BR>FINISH<BR>/prep7 <BR>upgeom,OFFSET/DMAX,1,1,beammodel,rst <BR>! 非线性求解<BR>FINISH <BR>/SOLU <BR>!* <BR>FORCE=FORCE*3.<BR>DK,3, , , ,0,UX,UY,UZ, , ,ROTZ , <BR>DK,2, , , ,0,UX,UY, , , , , <BR>FK,2,FZ,-FORCE <BR>ANTYPE,0<BR>NLGEOM,1<BR>NSUBST,20,0,0 <BR>OUTRES,ALL,1<BR>ARCLEN,1,0,0<BR>AUTOTS,-1.0 <BR>SOLVE <BR>! 绘制荷载位移曲线<BR>FINISH<BR>/POST26 <BR>FILE<BR>FILE,'beammodel','rst','.' <BR>/UI,COLL,1 <BR>NUMVAR,200 <BR>FILLDATA,191,,,,1,1 <BR>REALVAR,191,191 <BR>NUMVAR,200 <BR>FILLDATA,191,,,,1,1 <BR>REALVAR,191,191 <BR>!* <BR>NSOL,2,2,U,Z, UZ_2 <BR>STORE,MERGE <BR>!* <BR>RFORCE,3,19,F,Z, FZ_3 <BR>STORE,MERGE <BR>XVAR,2 <BR>PLVAR,3,</P>