机电系统动力学仿真matlab课后答案 刘白雁

2.5

习题三 3.1

clf,clc,clear

t=(0:18/100:18)'; xi=0.2:0.2:0.8;

beita=sqrt(1-xi.^2); sita=atan(beita./xi);

y=1-exp(-t*xi).*sin(t*beita+ones(101,1)*sita)./(ones(101,1)*beita); figure(1)

plot(t,y(:,1),'b:',t,y(:,2),'r-.',t,y(:,3),'g-',t,y(:,4),'ko')

legend('\\xi=0.2','\\xi=0.4','\\xi=0.6','\\xi=0.8')

1.61.4?=0.2?=0.4?=0.6?=0.81.210.80.60.40.20024681012141618

3.2

clf,clear x=-50:1:50; y=-40:1:60;

z=1./(sqrt((1-x).^2+y.^2)+sqrt((1+x).^2+y.^2)); figure(1)

plot3(x,y,z),box on [X,Y]=meshgrid(x,y);

Z=1./(sqrt((1-X).^2+Y.^2)+sqrt((1+X).^2+Y.^2)); figure(2) mesh(X,Y,Z) figure(3) surf(Z)

0.080.060.040.020100500-50-50050

0.50.40.30.20.10100500-50-50050