ANSYS动力学分析的几个入门例子问题一:悬臂梁受重力作用发生大变形,求其固有频率。图片附件:1.jpg(4.85K)基本过程:1、建模2、静力分析NLGEOM,ONSTRES,ON3、求静力解4、开始新的求解:modalSTRES,ONUPCOORD,1,ON修正坐标SOLVE...5、扩展模态解6、察看结果/PREP7ET,1,BEAM189!使用beam189梁单元MPTEMP,,,,,,,,MPTEMP,1,0MPDATA,EX,1,,210e9MPDATA,PRXY,1,,0.3MPDATA,DENS,1,,7850SECTYPE,1,BEAM,RECT,secA,0!定义梁截面secASECOFFSET,CENTSECDATA,0.005,0.01,0,0,0,0,0,0,0,0K,,,,,!建模与分网K,,2,,,K,,2,1,,LSTR,1,2LATT,1,,1,,3,,1LESIZE,1,,,20,,,,,1LMESH,1FINISH/SOL!静力大变形求解ANTYPE,0NLGEOM,1PSTRES,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,1AUTOTS,1NSUBST,20,,,1KBC,0SOLVEFINISH/SOLUTIONANTYPE,2!进行模态求解MSAVE,0MODOPT,LANB,10MXPAND,10,,,0!取前十阶模态PSTRES,1!打开预应力效应MODOPT,LANB,10,0,0,,OFFUPCOORD,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/SOLUEXPASS,1!扩展模态解PSOLVE,EIGEXPFINISH/POST1SET,LIST!观察结果FINISH问题二:循环对称结构模态分析这是ANSYSHELP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。图片附件:2.gif(18.74K)基本过程:1、建模2、definecyclic3、定义约束4、求模态解5、展开并察看结果r1=5!建模r2=10d1=2nsect=24alpha_deg=360/nsectalpha_rad=2*acos(-1)/nsect/prep7csys,1k,1,0,0,0k,2,0,0,d1k,3,r1,0,0k,4,r1,0,d1l,3,4arotat,1,,,,,,1,2,alpha_deg/2k,7,r2,0,0k,8,r2,0,d1l,7,8arotat,5,,,,,,1,2,alpha_deg/2arotat,2,,,,,,1,2,alpha_deg/2arotat,6,,,,,,1,2,alpha_deg/2a,5,6,10,9mshkey,1et,1,181r,1,0.20r,2,0.1mp,ex,1,10e6mp,prxy,1,0.3mp,dens,1,1e-4esize,0.5asel,,,,1,4aatt,,1asel,,,,5aatt,,2allselCYCLIC,,,,'CYCLIC'!定义基本扇区AMESH,all!分网FINISH/SOL!求模态解ANTYPE,2MODOPT,LANB,10MXPAND,10,,,0PSTRES,0MODOPT,LANB,10,0,0,,OFFDK,5,,,,0,UZ,,,,,,SOLVEFINISH/POST1SET,LISTSET,,,1,,,,4,/CYCEXPAND,,ONPLNS,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,BEAM189ET,2,SHELL93R,1,0.01,,,,,,MP,EX,1,210e9MP,PRXY,1,0.3MP,DENS,1,7850SECTYPE,1,BEAM,RECT,secA,0SECOFFSET,CENTSECDATA,0.005,0.008,0,0,0,0,0,0,0,0K,,-0.5,,,K,,0.5,,,K,,,,1,K,,,1,1,K,,-0.5,1,,K,,0.5,1,,K,,,,0.5,A,4,5,6LSTR,1,5LSTR,3,4LSTR,2,6LSEL,S,LINE,,4,6LATT,1,1,1,,7,,1LSEL,,,,ALLLESIZE,ALL,,,10,,,,,1LMESH,4,6TYPE,2MSHAPE,0,2DMSHKEY,1AMESH,1FINISH/SOL!为了使用模态叠加法谐分析ANTYPE,2MODOPT,LANB,20!先取结构前20阶模态MXPAND,20,,,0MODOPT,LANB,20,0,0,,OFFKSEL,S,KP,,1,3DK,ALL,,,,0,ALL,,,,,,SOLVEFINISH!/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,3HROPT,MSUPHROUT,ONHROPT,MSUP,20,,HROUT,ON,OFF,0F,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,1ALPHAD,5,SOLVEFINISH/POST26!察看位移响应FILE,,rfrqNUMVAR,20NSOL,2,139,U,Y,PLVAR,2FINISH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,BEAM189ET,2,SHELL93R,1,0.01,,,,,,MP,EX,1,210e9MP,PRXY,1,0.3MP,DENS,1,7850SECTYPE,1,BEAM,RECT,secA,0SECOFFSET,CENTSECDATA,0.005,0.008,0,0,0,0,0,0,0,0K,,-0.5,,,K,,0.5,,,K,,,,1,K,,,1,1,K,,-0.5,1,,K,,0.5,1,,K,,,,0.5,A,4,5,6LSTR,1,5LSTR,3,4LSTR,2,6LSEL,S,LINE,,4,6LATT,1,1,1,,7,,1LSEL,,,,ALLLESIZE,ALL,,,10,,,,,1LMESH,4,6TYPE,2MSHAPE,0,2DMSHKEY,1AMESH,1FINISH/SOL!取前十阶模态ANTYPE,2MODOPT,LANB,10KSEL,S,KP,,1,3DK,ALL,,,,0,ALL,,,,,,SOLVEFINISH/SOL!谱分析ANTYPE,8SPOPT,SPRS,10,1SVTYP,3SED,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,SOLVEFINISH/SOL!扩展模态ANTYPE,2EXPASS,1MXPAND,10,0,0,1,0.001,SOLVEFINISH/SOL!模态合并ANTYPE,8SRSS,0.001,DISPSOLVE/POST1!观察结果SET,LIST/INPUT,,mcomPRRSOL,FFINISH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,BEAM189ET,2,SHELL93R,1,0.01,,,,,,MP,EX,1,210e9MP,PRXY,1,0.3MP,DENS,1,7850SECTYPE,1,BEAM,RECT,secA,0SECOFFSET,CENTSECDATA,0.005,0.008,0,0,0,0,0,0,0,0K,,-0.5,,,K,,0.5,,,K,,,,1,K,,,1,1,K,,-0.5,1,,K,,0.5,1,,K,,,,0.5,A,4,5,6LSTR,1,5LSTR,3,4LSTR,2,6LSEL,S,LINE,,4,6LATT,1,1,1,,7,,1LSEL,,,,ALLLESIZE,ALL,,,10,,,,,1LMESH,4,6TYPE,2MSHAPE,0,2DMSHKEY,1AMESH,1FINISH/SOLANTYPE,4TRNOPT,FULL!完全法瞬态分析KSEL,S,KP,,1,3DK,ALL,,,,0,ALL,,,,,,OUTRES,ALL,1ALPHAD,5,!α阻尼TIME,2!定义载荷曲线AUTOTS,1NSUBST,50,,,1KBC,0SFA,ALL,1,PRES,500LSWRITE,1,TIME,3LSWRITE,2,TIME,4SFA,ALL,1,PRES,150KBC,1LSWRITE,3,TIME,5SFA,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,uyyPLVAR,2FINISH图片附件:5.jpg(22.16K)