Ansys里模态质量矩阵的提取方法

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Ansys里模态质量矩阵的提取方法
& N7 N5 m  H& n; }& H: [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：
2 H/ r) m* ?2 b0 f0 Q* h1、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：
- W8 F/ ^# N$ k& w/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
, f( y8 K5 G1 ?1 NET,1,COMBIN14,,,2
# t; V/ ?5 B, p* _( T) N- M" ZET,2,MASS21,,,4
R,1,200 ! SPRING CONSTANT = 200
8 Q2 u  i% }' h6 U; lR,2,800 ! SPRING CONSTANT = 800
R,3,.5 ! MASS = .5
R,4,1 ! MASS = 1
N,1
- J2 g( G9 G' O# f4 j. ~N,4,1
  B8 x* ^7 a3 v- G( f! DFILL
2 k, V1 h( q6 U. fE,1,2 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)
5 [, l" c' B( I- [* v) ~/ tTYPE,2
% l9 Q& m2 b9 B6 b4 A) HREAL,3
8 i; `  D& o* ^2 YE,2 ! MASS ELEMENT (TYPE,2) AND MASS = .5 (REAL,3)
TYPE,1
3 Q7 D4 k- i7 X6 \% H0 AREAL,2
7 V7 K; H5 R3 s4 L! o6 m9 u: TE,2,3 ! SPRING ELEMENT (TYPE,1) AND K = 800 (REAL,2)
& S4 U" R. R, ^6 P9 L  b$ p) S* D0 oTYPE,2
REAL,4
: o( O# j+ Y; q! BE,3 ! MASS ELEMENT (TYPE,2) AND MASS = 1 (REAL,4)
$ G# u3 |: Z/ f4 }TYPE,1
REAL,1
5 W$ j0 P' W4 eE,3,4 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)
4 B! ~, ]% H1 f% o* _9 \M,2,UX,3
) D7 u# [7 @3 ?, H& ], L. z( KOUTPR,BASIC,1
) x  G! [3 A& G: ^7 UD,1,UY,,,4
( J7 @6 v, Y8 [. V" w4 qD,1,UX,,,4,3
FINISH
/SOLU
ANTYPE,MODAL
" @. C4 A- Y/ ?: e4 P+ c: jMODOPT,subspa,2,,,2,ON
MXPAND,2,,,YES
SOLVE
FINISH
/post1
set,1,1
etabl,kene,kene
ssum
. v+ a  H% {0 ~. k5 E6 k$ q8 n*get,keneval1,ssum,,item,kene
1 `+ r. p8 t8 t) L+ w/ t*get,freqval1,mode,1,freq
eigen1=(2*3.14159*freqval1)**2
pmass1=2*keneval1/eigen1
* [7 F# P$ x9 Z( u9 a$ W) [0 A! bset,1,2
# D) ?1 Q  Q: K0 z& Aetabl,kene,kene
ssum
8 r* U+ G) y9 u*get,keneval2,ssum,,item,kene
*get,freqval2,mode,2,freq
eigen2=(2*3.14159*freqval2)**2
pmass2=2*keneval2/eigen2
finish