【推荐】ANSYS动力学分析的几个入门例子

https://www.aoxue.org/cgi-bin/bbs/topic_show.cgi?id=35504&h=1&bpg=1&age=0
  
问题一：悬臂梁受重力作用发生大变形，求其固有频率。  
  
基本过程：  
1、建模  
2、静力分析  
   NLGEOM,ON  
  &nbspSTRES,ON  
3、求静力解  
4、开始新的求解：modal  
  &nbspSTRES,ON  
   UPCOORD,1,ON 修正坐标  
  &nbspSOLVE...  
5、扩展模态解  
6、察看结果  
  
/PREP7  
ET,1,BEAM189 !使用beam189梁单元  
MPTEMP,,,,,,,,  
MPTEMP,1,0  
MPDATA,EX,1,,210e9  
MPDATA,PRXY,1,,0.3  
MPDATA,DENS,1,,7850  
SECTYPE, 1, BEAM, RECT, secA, 0 !定义梁截面secA  
SECOFFSET, CENT  
SECDATA,0.005,0.01,0,0,0,0,0,0,0,0  
K, ,,,, !建模与分网  
K, ,2,,,  
K, ,2,1,,  
LSTR, 1, 2  
LATT,1, ,1, , 3, ,1  
LESIZE,1, , ,20, , , , ,1  
LMESH, 1  
FINISH  
  
/SOL !静力大变形求解  
ANTYPE,0  
NLGEOM,1  
PSTRES,ON !计及预应力效果  
DK,1, , , ,0,ALL, , , , , ,  
ACEL,0,9.8,0, !只考虑重力作用  
TIME,1  
AUTOTS,1  
NSUBST,20, , ,1  
KBC,0  
SOLVE  
FINISH  
  
/SOLUTION  
ANTYPE,2 !进行模态求解  
MSAVE,0  
MODOPT,LANB,10  
MXPAND,10, , ,0 !取前十阶模态  
PSTRES,1 !打开预应力效应  
MODOPT,LANB,10,0,0, ,OFF  
UPCOORD,1,ON !修正坐标以得到正确的应力  
PSOLVE,TRIANG !三角化矩阵  
PSOLVE,EIGLANB !提取特征值和特征向量  
FINISH  
/SOLU  
EXPASS,1 !扩展模态解  
PSOLVE,EIGEXP  
FINISH  
  
/POST1  
SET,LIST !观察结果  
FINISH

问题二：循环对称结构模态分析  
这是ANSYS HELP里的例子，但那个命令流似乎有些问题，下面是整理过的命令流。  
  
基本过程：  
1、建模  
2、define cyclic  
3、定义约束  
4、求模态解  
5、展开并察看结果  
  
r1=5 !建模  
r2=10  
d1=2  
nsect=24  
alpha_deg=360/nsect  
alpha_rad=2*acos(-1)/nsect  
  
/prep7  
csys,1  
k,1,0,0,0  
k,2,0,0,d1  
k,3,r1,0,0  
k,4,r1,0,d1  
l,3,4  
arotat,1,,,,,,1,2,alpha_deg/2  
k,7,r2,0,0  
k,8,r2,0,d1  
l,7,8  
arotat,5,,,,,,1,2,alpha_deg/2  
arotat,2,,,,,,1,2,alpha_deg/2  
arotat,6,,,,,,1,2,alpha_deg/2  
a,5,6,10,9  
mshkey,1  
et,1,181  
r,1,0.20  
r,2,0.1  
mp,ex,1,10e6  
mp,prxy,1,0.3  
mp,dens,1,1e-4  
esize,0.5  
asel,,,,1,4  
aatt,,1  
asel,,,,5  
aatt,,2  
allsel  
  
CYCLIC, , , ,'CYCLIC' !定义基本扇区  
AMESH,all !分网  
FINISH  
  
/SOL !求模态解  
ANTYPE,2  
MODOPT,LANB,10  
MXPAND,10, , ,0  
PSTRES,0  
MODOPT,LANB,10,0,0, ,OFF  
DK,5, , , ,0,UZ, , , , , ,  
SOLVE  
FINISH  
  
/POST1  
SET,LIST  
SET, , ,1, , , ,4,  
/CYCEXPAND, ,ON  
PLNS,U,SUM !观察扩展模态  
FINISH

问题三：三角平台受谐波载荷作用,求结构响应  
谐波载荷为作用在平台上面一点的集中力，幅值为10N，频率范围5Hz~70Hz  
  
基本过程：  
1、建模  
2. 求模态解  
3、用模态叠加法作谐分析  
4. 观察结果  
  
/PREP7 !建模  
ET,1,BEAM189  
ET,2,SHELL93  
R,1,0.01, , , , , ,  
MP,EX,1,210e9  
MP,PRXY,1,0.3  
MP,DENS,1,7850  
SECTYPE, 1, BEAM, RECT, secA, 0  
SECOFFSET, CENT  
SECDATA,0.005,0.008,0,0,0,0,0,0,0,0  
K, ,-0.5,,,  
K, ,0.5,,,  
K, ,,,1,  
K, ,,1,1,  
K, ,-0.5,1,,  
K, ,0.5,1,,  
K, ,,,0.5,  
A,4,5,6  
LSTR, 1, 5  
LSTR, 3, 4  
LSTR, 2, 6  
LSEL,S,LINE,,4,6  
LATT,1,1,1, , 7, ,1  
LSEL, , , ,ALL  
LESIZE,ALL, , ,10, , , , ,1  
LMESH,4,6  
TYPE, 2  
MSHAPE,0,2D  
MSHKEY,1  
AMESH,1  
FINISH  
  
/SOL !为了使用模态叠加法谐分析  
ANTYPE,2  
MODOPT,LANB,20 !先取结构前20阶模态  
MXPAND,20, , ,0  
MODOPT,LANB,20,0,0, ,OFF  
KSEL,S,KP,,1,3  
DK,ALL, , , ,0,ALL, , , , , ,  
SOLVE  
FINISH  
  
!/POST1 !最好事先看一下模态结果  
!SET,LIST !以了解模态频率范围  
!FINISH  
  
/SOL !模态叠加法谐响应分析  
ANTYPE,3  
HROPT,MSUP  
HROUT,ON  
HROPT,MSUP,20, ,  
HROUT,ON,OFF,0  
F,177,FY,-10, !施加10N的力在节点177的负Y方向  
HARFRQ,5,70, !载荷的强制频率范围  
NSUBST,200,  
KBC,1  
ALPHAD,5,  
SOLVE  
FINISH  
  
/POST26 !察看位移响应  
FILE,,rfrq  
NUMVAR,20  
NSOL,2,139,U,Y,  
PLVAR,2  
FINISH

问题四：三角平台受一地震谱激励,求应力分布和支反力  
  
基本过程：  
1、建模  
2、求模态解  
3、求谱解  
4、扩展模态  
5、模态合并  
6、观察结果  
  
/PREP7 !建模  
ET,1,BEAM189  
ET,2,SHELL93  
R,1,0.01, , , , , ,  
MP,EX,1,210e9  
MP,PRXY,1,0.3  
MP,DENS,1,7850  
SECTYPE, 1, BEAM, RECT, secA, 0  
SECOFFSET, CENT  
SECDATA,0.005,0.008,0,0,0,0,0,0,0,0  
  
K, ,-0.5,,,  
K, ,0.5,,,  
K, ,,,1,  
K, ,,1,1,  
K, ,-0.5,1,,  
K, ,0.5,1,,  
K, ,,,0.5,  
A,4,5,6  
LSTR, 1, 5  
LSTR, 3, 4  
LSTR, 2, 6  
LSEL,S,LINE,,4,6  
LATT,1,1,1, , 7, ,1  
LSEL, , , ,ALL  
LESIZE,ALL, , ,10, , , , ,1  
LMESH,4,6  
TYPE, 2  
MSHAPE,0,2D  
MSHKEY,1  
AMESH,1  
FINISH  
  
/SOL !取前十阶模态  
ANTYPE,2  
MODOPT,LANB,10  
KSEL,S,KP,,1,3  
DK,ALL, , , ,0,ALL, , , , , ,  
SOLVE  
FINISH  
  
/SOL !谱分析  
ANTYPE,8  
SPOPT,SPRS,10,1  
SVTYP,3  
SED,0,1,0, !给出激励方向  
FREQ,0.25,1.34,6.73,14.6,28.9,0,0,0,0 !激励谱  
SV,0,0.00073,0.00016,0.00034,0.00034,0.00052,  
SOLVE  
FINISH  
  
/SOL !扩展模态  
ANTYPE,2  
EXPASS,1  
MXPAND,10,0,0,1,0.001,  
SOLVE  
FINISH  
  
/SOL !模态合并  
ANTYPE,8  
SRSS,0.001,DISP  
SOLVE  
  
/POST1 !观察结果  
SET,LIST  
/INPUT,,mcom  
PRRSOL,F  
FINISH

问题五：三角平台受时程载荷作用,求应力分布和变形过程  
  
基本过程：  
1、建模  
2. 施加随时间变化载荷，定义载荷步  
3、求解  
4. 在POST1和POST26中观察结果  
  
/PREP7 !建模  
ET,1,BEAM189  
ET,2,SHELL93  
R,1,0.01, , , , , ,  
MP,EX,1,210e9  
MP,PRXY,1,0.3  
MP,DENS,1,7850  
SECTYPE, 1, BEAM, RECT, secA, 0  
SECOFFSET, CENT  
SECDATA,0.005,0.008,0,0,0,0,0,0,0,0  
K, ,-0.5,,,  
K, ,0.5,,,  
K, ,,,1,  
K, ,,1,1,  
K, ,-0.5,1,,  
K, ,0.5,1,,  
K, ,,,0.5,  
A,4,5,6  
LSTR, 1, 5  
LSTR, 3, 4  
LSTR, 2, 6  
LSEL,S,LINE,,4,6  
LATT,1,1,1, , 7, ,1  
LSEL, , , ,ALL  
LESIZE,ALL, , ,10, , , , ,1  
LMESH,4,6  
TYPE, 2  
MSHAPE,0,2D  
MSHKEY,1  
AMESH,1  
FINISH  
  
/SOL  
ANTYPE,4  
TRNOPT,FULL !完全法瞬态分析  
KSEL,S,KP,,1,3  
DK,ALL, , , ,0,ALL, , , , , ,  
OUTRES,ALL,1  
ALPHAD,5, !α阻尼  
  
TIME,2 !定义载荷曲线  
AUTOTS,1  
NSUBST,50, , ,1  
KBC,0  
SFA,ALL,1,PRES,500  
LSWRITE,1,  
  
TIME,3  
LSWRITE,2,  
  
TIME,4  
SFA,ALL,1,PRES,150  
KBC,1  
LSWRITE,3,  
  
TIME,5  
SFA,ALL,1,PRES,  
LSWRITE,4,  
  
LSSOLVE,1,4,1, !求解  
FINISH  
     
/POST26 !观察变形随时间的变化  
NSOL,2,177,U,Y,uyy  
PLVAR,2  
FINISH