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：

1、利用SSUM对ETABLE 动能数据求和获得结构总动能( 1/2m*ω*ω)

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。

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 SYSTEM

C*** VIBRATION THEORY AND APPLICATIONS, THOMSON, 2ND PRINTING, PAGE 163,EX 6.2-2

ET,1,COMBIN14,,,2

ET,2,MASS21,,,4

R,1,200 ! SPRING CONSTANT = 200

R,2,800 ! SPRING CONSTANT = 800

R,3,.5 ! MASS = .5

R,4,1 ! MASS = 1

N,1

N,4,1

FILL

E,1,2 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)

TYPE,2

REAL,3

E,2 ! MASS ELEMENT (TYPE,2) AND MASS = .5 (REAL,3)

TYPE,1

REAL,2

E,2,3 ! SPRING ELEMENT (TYPE,1) AND K = 800 (REAL,2)

TYPE,2

REAL,4

E,3 ! MASS ELEMENT (TYPE,2) AND MASS = 1 (REAL,4)

TYPE,1

REAL,1

E,3,4 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)

M,2,UX,3

OUTPR,BASIC,1

D,1,UY,,,4

D,1,UX,,,4,3

FINISH

/SOLU

ANTYPE,MODAL

MODOPT,subspa,2,,,2,ON

MXPAND,2,,,YES

SOLVE

FINISH

/post1

set,1,1

etabl,kene,kene

ssum

*get,keneval1,ssum,,item,kene

*get,freqval1,mode,1,freq

eigen1=(2*3.14159*freqval1)**2

pmass1=2*keneval1/eigen1

set,1,2

etabl,kene,kene

ssum

*get,keneval2,ssum,,item,kene

*get,freqval2,mode,2,freq

eigen2=(2*3.14159*freqval2)**2

pmass2=2*keneval2/eigen2

finish

多指教