% 无阻尼二自由系统固有频率的程序 20180401A
) _ m# g+ f) y+ f8 Wm1=100;m2=100;k1=200;k2=400;%
0 s* a0 d* R9 L7 O8 @$ _c1=0;c2=0;! P5 W. _" l O9 J
x0=[1;0];xd0=[0;0];tf=50;dt=0.1;" ]# C* F0 P% X3 @& y7 y
M=[m1,0;0,m2];k=[k1+k2,-k2;-k2,k2];
- [) S+ m' Q$ Tc=[c1+c2,-c2;-c2,c2];
5 B, [7 K D( i) W- _A=[zeros(2,2),eye(2);-M\k,-M\c];% G- B! O5 S: M! U
y0=[x0;xd0];- y2 ~: G. a' t
for i=1:round(tf/dt)+1
6 H) _. `. m8 O. ^. Z8 W t(i)=dt*(i-1). C% z. P5 W! W; ?
y(:,i)=expm(A*t(i))*y0;
% ]3 \, Z# h) ], n/ N7 C8 l' }end! r4 y- `% K0 Z, C
subplot(2,1,1),plot(t,y(1, ),grid 4 s) x( G- q Y; J' v% z1 L" M
subplot(2,1,2),plot(t,y(2,),grid( v1 [3 Q- R: ]5 l9 l2 E
[p,lamda]=eig(A)
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+ t; H) {% C) O1 ?1 R/ W( v
6 J5 c0 v' a' L2 @3 slamda =; U3 e9 }! t1 D
Columns 1 through 28 O4 r& P, Q* h3 Q
0.000000000000000 + 3.020447918044219i 0.000000000000000 + 0.000000000000000i- H+ y" u% p! @5 _$ U
0.000000000000000 + 0.000000000000000i 0.000000000000000 - 3.020447918044219i
p3 c& t; P# |) J6 Y8 X3 Q' m 0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i+ d5 H* {8 b' D( N, ]
0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i
. |: Y" s3 k' _ Columns 3 through 4
0 E2 W3 p. v: f5 J 0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i
+ P$ \) g9 V2 S 0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i
# C( h" O) I4 O' I -0.000000000000000 + 0.936426384924271i 0.000000000000000 + 0.000000000000000i0 |8 [; ~3 |# j* R$ C
0.000000000000000 + 0.000000000000000i -0.000000000000000 - 0.936426384924271i
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发表于 2018-4-16 19:41:12
