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
3 u9 G7 q2 K: m) z4 @! r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：
+ P" A  V3 K4 D  w4 w2 ]9 @1、利用SSUM对ETABLE 动能数据求和获得结构总动能( 1/2m*ω*ω)
3 ~( {2 D- w9 A' A; @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
' H$ Q& J* ]2 {& r9 ]! sC*** VIBRATION THEORY AND APPLICATIONS, THOMSON, 2ND PRINTING, PAGE 163,EX 6.2-2
ET,1,COMBIN14,,,2
1 b  b2 J( t; q$ @  D* LET,2,MASS21,,,4
R,1,200 ! SPRING CONSTANT = 200
) K0 C: Y6 l6 _R,2,800 ! SPRING CONSTANT = 800
R,3,.5 ! MASS = .5
# ~/ S1 L% C" c' o) b9 c9 uR,4,1 ! MASS = 1
N,1
N,4,1
FILL
/ ]/ l- ?5 h/ G/ W0 A( F2 J' oE,1,2 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)
( A1 i5 K, T( z1 y! \2 ZTYPE,2
REAL,3
E,2 ! MASS ELEMENT (TYPE,2) AND MASS = .5 (REAL,3)
TYPE,1
; k% b  ~1 T& F" ]1 BREAL,2
  X4 K# ~0 c) k$ h1 P: ^7 rE,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)
8 ^8 Z, n" \: C) V: H2 D- c* h0 JTYPE,1
REAL,1
$ V" A, v; Z8 \: |" wE,3,4 ! SPRING ELEMENT (TYPE,1) AND K = 200 (REAL,1)
M,2,UX,3
7 C" {9 D: ^0 U6 n2 w( ?5 \* y7 cOUTPR,BASIC,1
D,1,UY,,,4
D,1,UX,,,4,3
FINISH
/SOLU
ANTYPE,MODAL
. ^$ a2 [" [. }: DMODOPT,subspa,2,,,2,ON
. H# Y8 Y& O, w4 ^MXPAND,2,,,YES
* T9 p5 N3 O% t/ aSOLVE
FINISH
0 u; X2 [8 l, F* t2 y/post1
/ A: G0 b8 u- C; m" {- bset,1,1
+ ^/ u* i- y& V. Q5 i' Tetabl,kene,kene
ssum
*get,keneval1,ssum,,item,kene
*get,freqval1,mode,1,freq
/ M5 ?6 x! u1 w( c% H2 _3 qeigen1=(2*3.14159*freqval1)**2
0 ]7 ~) I9 E6 E; f5 p6 s7 |( Fpmass1=2*keneval1/eigen1
; n5 b3 g3 n, J- f/ tset,1,2
etabl,kene,kene
ssum
*get,keneval2,ssum,,item,kene
7 T6 W8 y! C: Z7 p3 ~' h& A$ J*get,freqval2,mode,2,freq
eigen2=(2*3.14159*freqval2)**2
) O  U3 R; a& O# G9 z6 t7 dpmass2=2*keneval2/eigen2
: w9 R, b9 z; e, y+ p3 Ffinish