[转帖]模态质量矩阵的提取方法
我知道模态质量矩阵的提取方法，请大家分享：模态分析过程中打开振型型则化开关(MODOPT命令的Nrmkey设置为ON)，ANSYS程序将自动将每阶模态的最大位移单位化，就可以提取模态质量。计算方法如下： <BR>1、利用SSUM对ETABLE 动能数据求和获得结构总动能( 1/2m*ω*ω) <BR>2、将结构总动能除以1/2m*ω*ω得到m ，其中ω 是系统的角频率。 <BR>下面是《ANSYS Verification Manual》中VM89.DAT稍加修改后提取模态质量的例子： <BR><BR>/PREP7 <BR>/TITLE, VM89, NATURAL FREQUENCIES OF A TWO-MASS-SPRING SYSTEM <BR>C*** VIBRATION THEORY AND APPLICATIONS, THOMSON, 2ND PRINTING, PAGE 163,EX 6.2-2 <BR>ET,1,COMBIN14,,,2 <BR>ET,2,MASS21,,,4 <BR>R,1,200 ! SPRING CONSTANT = 200 <BR>R,2,800 ! SPRING CONSTANT = 800 <BR>R,3,.5 ! MASS = .5 <BR>R,4,1 ! MASS = 1 <BR>N,1 <BR>N,4,1 <BR>FILL <BR>E,1,2 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1) <BR>TYPE,2 <BR>REAL,3 <BR>E,2 ! MASS ELEMENT (TYPE,2) AND MASS = .5 (REAL,3) <BR>TYPE,1 <BR>REAL,2 <BR>E,2,3 ! SPRING ELEMENT (TYPE,1) AND K = 800 (REAL,2) <BR>TYPE,2 <BR>REAL,4 <BR>E,3 ! MASS ELEMENT (TYPE,2) AND MASS = 1 (REAL,4) <BR>TYPE,1 <BR>REAL,1 <BR>E,3,4 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1) <BR>M,2,UX,3 <BR>OUTPR,BASIC,1 <BR>D,1,UY,,,4 <BR>D,1,UX,,,4,3 <BR>FINISH <BR><BR>/SOLU <BR>ANTYPE,MODAL <BR>MODOPT,subspa,2,,,2,ON <BR>MXPAND,2,,,YES <BR>SOLVE <BR>FINISH <BR><BR>/post1 <BR><BR>set,1,1 <BR>etabl,kene,kene <BR>ssum <BR>*get,keneval1,ssum,,item,kene <BR>*get,freqval1,mode,1,freq <BR>eigen1=(2*3.14159*freqval1)**2 <BR>pmass1=2*keneval1/eigen1 <BR><BR>set,1,2 <BR>etabl,kene,kene <BR>ssum <BR>*get,keneval2,ssum,,item,kene <BR>*get,freqval2,mode,2,freq <BR>eigen2=(2*3.14159*freqval2)**2 <BR>pmass2=2*keneval2/eigen2 <BR><BR>finish <BR> UP <P>看哪个都挺好的!呵呵</P> <P>very good!<BR><BR>thank you!</P> ＣＯＭＢＩＮ１４单元为什么不定义ＭＰ呢？是不是ＣＯＭＢＩＮ１４中的ＤＡＭＰ值不必定义呢？请指教！ 动能公式不是速度的平方吗？和角频率没有关系吧！ 楼主你重新编辑下把，发的东西看的眼花啊
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