柱子稳定分析算

! 要点：预应力，特征值屈曲，添加初始缺陷，几何非线性分析

finish 
/CLEAR 
/UNITS,SI 
/PREP7 
!* 
FORCE=100 
OFFSET=0.1 !初始缺陷为 0.1 
! 建立模型 
ET,1,BEAM4 
ET,2,LINK10 
R,1,0.1*0.12,0.12*0.1**3/12,0.1*0.12**3/12,0.12,0.1, , 
R,2,0.002*0.002,2e-3, !预应力 
MPTEMP,1,0 
MPDATA,EX,1,,200e9 
MPDATA,PRXY,1,,0.27 
MPDATA,DENS,1,,7800 
k,1, 
k,2,0,0,5 
k,3,0,0,-5 
k,11,0.2,0,0 
k,12,-0.2,0,0 
k,13,0,0.2 
k,15,0,-0.2 
l,1,2 
l,1,3 
l,1,11 
l,1,12 
l,1,13 
l,1,15 270 
l,2,11 
l,2,12 
l,2,13 
l,2,15 
l,3,11 
l,3,12 
l,3,13 
l,3,15 
lsel,,,,1,6 
latt,1,1,1 
ALLSEL,ALL 
lsel,,,,7,14 
latt,1,2,2 
ALLSEL,ALL 
lsel,,,,1,6 
LESIZE,all,0.3, , , , , , ,1 
lsel,,,,7,14 
LESIZE,all, , ,1 , , , , ,1 
ALLSEL,ALL 
LMESH,ALL 
FINISH 
/ESHAPE,1.0 
!* 
! 求解特征值屈曲荷载 
*DO,I,1,100 
FINISH 
/SOLU 
DK,3, , , ,0,UX,UY,UZ, , ,ROTZ , 
DK,2, , , ,0,UX,UY, , , , , 
FK,2,FZ,-FORCE 
ANTYPE,0 
!设定时间步 
TIME,1 
AUTOTS,0 
NSUBST,1, , ,1 
!NLGEOM,1 
SSTIF,ON 
SOLVE 
FINISH 
/SOLU 
ANTYPE,BUCKLE ! Buckling analysis 271 
BUCOPT,LANB,1 ! Use Block Lanczos solution method, extract 1 mode 
MXPAND,1 ! Expand 1 mode shape 
PSTRES,ON ! INCLUDE PRESTRESS EFFECTS 
SOLVE 
FINISH 
*GET,FREQ1,MODE,1,FREQ 
*IF,FREQ1,LT,0.01,THEN 
FREQ1=0.01 
*ENDIF 
*IF,ABS(FREQ1-1),LT,0.01,THEN !如果频率误差小于 1% 
*EXIT 
*ENDIF 
FORCE=FORCE*FREQ1 
*ENDDO 
! 添加初始缺陷 
FINISH 
/POST1 
SET,FIRST 
NSORT,U,SUM 
*GET,DMAX,SORT, ,MAX 
!* 
FINISH 
/prep7 
upgeom,OFFSET/DMAX,1,1,beammodel,rst 
! 非线性求解 
FINISH 
/SOLU 
!* 
FORCE=FORCE*3. 
DK,3, , , ,0,UX,UY,UZ, , ,ROTZ , 
DK,2, , , ,0,UX,UY, , , , , 
FK,2,FZ,-FORCE 
ANTYPE,0 
NLGEOM,1 
NSUBST,20,0,0 
OUTRES,ALL,1 
ARCLEN,1,0,0 
AUTOTS,-1.0 
SOLVE 272 
! 绘制荷载位移曲线 
FINISH 
/POST26 
FILE 
FILE,'beammodel','rst','.' 
/UI,COLL,1 
NUMVAR,200 
FILLDATA,191,,,,1,1 
REALVAR,191,191 
NUMVAR,200 
FILLDATA,191,,,,1,1 
REALVAR,191,191 
!* 
NSOL,2,2,U,Z, UZ_2 
STORE,MERGE 
!* 
RFORCE,3,19,F,Z, FZ_3 
STORE,MERGE 
XVAR,2 
PLVAR,3, 

作者:XuJC