ansys使用技巧：xjq15_rhtq

如何提取模态质量 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：1、利用SSUM对ETABLE 动能数据求和获得结构总动能(
）；2、将结构总动能除以
得到
，其中
是系统的角频率。 下面是《ANSYS Verification Manual》中VM89.DAT稍加修改后提取模态质量的例子：?/PREP7/TITLE, VM89, NATURAL FREQUENCIES OF A TWO-MASS-SPRING SYSTEMC*** VIBRATION THEORY AND APPLICATIONS, THOMSON, 2ND PRINTING, PAGE 163,EX 6.2-2ET,1,COMBIN14,,,2ET,2,MASS21,,,4R,1,200 ! SPRING CONSTANT = 200R,2,800 ! SPRING CONSTANT = 800R,3,.5 ! MASS = .5R,4,1 ! MASS = 1N,1N,4,1FILLE,1,2 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)TYPE,2REAL,3E,2 ! MASS ELEMENT (TYPE,2) AND MASS = .5 (REAL,3)TYPE,1REAL,2E,2,3 ! SPRING ELEMENT (TYPE,1) AND K = 800 (REAL,2)TYPE,2REAL,4E,3 ! MASS ELEMENT (TYPE,2) AND MASS = 1 (REAL,4)TYPE,1REAL,1E,3,4 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)M,2,UX,3OUTPR,BASIC,1D,1,UY,,,4D,1,UX,,,4,3FINISH/SOLUANTYPE,MODAL?MODOPT,subspa,2,,,2,ONMXPAND,2,,,YESSOLVEFINISH/post1set,1,1etabl,kene,kenessum?*get,keneval1,ssum,,item,kene*get,freqval1,mode,1,freqeigen1=(2*3.14159*freqval1)**2pmass1=2*keneval1/eigen1set,1,2etabl,kene,kenessum*get,keneval2,ssum,,item,kene*get,freqval2,mode,2,freqeigen2=(2*3.14159*freqval2)**2pmass2=2*keneval2/eigen2finish