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
' `1 M7 ?- R/ @2 F1 J2 S- z" `5 N- b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)
6 ]" X/ {" N' [! \% @+ N) O2、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。
0 u* T3 b6 H; g1 N# ^下面是《ANSYS Verification Manual》中VM89.DAT稍加修改后提取模态质量的例子：
% v& S4 d9 t* J1 x' b/PREP7
5 @) c$ N# A' m0 y/TITLE, VM89, NATURAL FREQUENCIES OF A TWO-MASS-SPRING SYSTEM
3 y( C4 E& S5 D& ~* I0 uC*** VIBRATION THEORY AND APPLICATIONS, THOMSON, 2ND PRINTING, PAGE 163,EX 6.2-2
ET,1,COMBIN14,,,2
% x1 ~3 @  p/ \; J- w$ gET,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
$ ~/ q* S5 I# z+ J! m+ F: `9 qN,1
N,4,1
. U% G6 l3 J4 M6 O! IFILL
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)
0 l" i# [2 |1 c6 V! [+ l6 YTYPE,1
/ E2 I5 F  ^* e1 i" }, s$ q+ u, hREAL,2
E,2,3 ! SPRING ELEMENT (TYPE,1) AND K = 800 (REAL,2)
+ Q  k' o/ y! i+ e5 HTYPE,2
: J2 |* F0 c6 |1 }' U/ iREAL,4
E,3 ! MASS ELEMENT (TYPE,2) AND MASS = 1 (REAL,4)
8 \* m8 E  u% @TYPE,1
& x' v0 z3 V- [' a0 e0 w& v5 XREAL,1
' r2 g& H% y: c# r! NE,3,4 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)
5 l0 T# [6 d* X# K+ ^4 zM,2,UX,3
OUTPR,BASIC,1
2 C3 |# J2 b: o; O9 WD,1,UY,,,4
- w* t6 r" L! W2 z4 P2 MD,1,UX,,,4,3
FINISH
2 d. H& L2 Y9 t/ h4 k+ {9 K. i/SOLU
ANTYPE,MODAL
2 M  [; F7 u0 E+ n, n8 O) cMODOPT,subspa,2,,,2,ON
MXPAND,2,,,YES
SOLVE
FINISH
/post1
set,1,1
etabl,kene,kene
ssum
*get,keneval1,ssum,,item,kene
- n' z" ~, x: Z" X*get,freqval1,mode,1,freq
eigen1=(2*3.14159*freqval1)**2
pmass1=2*keneval1/eigen1
set,1,2
etabl,kene,kene
% |3 t: b6 r! F; Bssum
% A4 Q! j& n5 S& }*get,keneval2,ssum,,item,kene
! x. f. b/ V- E& l8 P8 A0 j*get,freqval2,mode,2,freq
7 s# i4 T2 R+ [7 Seigen2=(2*3.14159*freqval2)**2
pmass2=2*keneval2/eigen2
finish