% 无阻尼二自由系统固有频率的程序 20180401A* N+ Z: s$ k4 R8 ~
m1=100;m2=100;k1=200;k2=400;% ; ~5 V7 W$ j/ x3 y2 G5 ^
c1=0;c2=0;4 R$ b, l8 K& B" ^
x0=[1;0];xd0=[0;0];tf=50;dt=0.1;& b1 L8 D' k) i! }* L/ ?% [
M=[m1,0;0,m2];k=[k1+k2,-k2;-k2,k2];' e6 H3 M8 ], |
c=[c1+c2,-c2;-c2,c2];
. c- S0 Q5 t2 O/ w9 i5 G- O& |8 NA=[zeros(2,2),eye(2);-M\k,-M\c];
3 S! L5 h) O8 H9 B o) Wy0=[x0;xd0];+ i' K& U7 S: t9 o* M$ s
for i=1:round(tf/dt)+1' h. b6 t( ?$ Q2 X) V5 L
t(i)=dt*(i-1)
! M6 w7 ^, V0 T# s* R y(:,i)=expm(A*t(i))*y0;
; x) q0 m2 m4 ~8 p) zend+ \ }$ ~" _1 @8 ^7 ]# R
subplot(2,1,1),plot(t,y(1, ),grid 8 _/ ^9 j/ t) [
subplot(2,1,2),plot(t,y(2,),grid
9 F4 w7 Z3 p3 h4 E1 @1 x[p,lamda]=eig(A)
?: H' W4 K, t+ N& M7 K* k6 _; z9 G) ]* U3 U* N
5 d& u v' v" N8 q8 H
& p3 q& F1 \* [0 }: v8 @0 l
0 S4 {0 @) C$ f% dlamda =
# V$ e6 G% o3 A- Y9 j! A" T9 Z Columns 1 through 27 a# d) f$ i# h1 W
0.000000000000000 + 3.020447918044219i 0.000000000000000 + 0.000000000000000i
$ d; h$ h- z' H: q3 K) n 0.000000000000000 + 0.000000000000000i 0.000000000000000 - 3.020447918044219i
; Z5 I! r3 A8 U; a 0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i
7 `* f: ~1 Q7 Y$ q7 h 0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i# f# z) |7 ?3 k1 p5 Y
Columns 3 through 40 a- N. B! E3 M" c$ o) Q
0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i' m, v: X$ _8 ~/ T
0.000000000000000 + 0.000000000000000i 0.000000000000000 + 0.000000000000000i
+ ]0 T. ~" g' B" o- v -0.000000000000000 + 0.936426384924271i 0.000000000000000 + 0.000000000000000i
& q2 B4 g0 h& J& a. x( H7 b# B& K 0.000000000000000 + 0.000000000000000i -0.000000000000000 - 0.936426384924271i
7 h, r. ^( u$ A: t% I& o( B6 V9 I$ r* x
7 |3 M9 o0 r# M0 ?
- L) t7 M( ~; K0 P6 o2 h7 K3 [- `0 S* c! c# o: j1 H& P# J) ?1 G
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发表于 2018-4-16 19:41:12
