耦合故障

zhuchang1121

function dz=dafen1(t,z)
m=32.1;
M=50;
c=1050;
k=6*10^6;
w=1400;
kr=4*10^7;
u=0.0002;
g=9.8;
f=0.12;
p=0.001;
q=0.0005;
cs1=350;
cs2=500;
ks1=7.4e7;
ks2=2.5e9;
if z(5)< 0
c3=cs1;
k3=ks1;
elseif  (z(5)>=0)&&(z(5)<=q)
c3=cs2;
k3=ks2;
else
c3=cs1;
k3=ks1;
end
e=sqrt(z(1)^2+z(3)^2);
if  e>=p
    N=kr*(e-p);
    Fx=-N*(z(1)-f*z(3))/e;
    Fy=-N*(f*z(1)+z(3))/e;
else
    N=0;
    Fx=0;
    Fy=0;
end
dx=zeros(6,1);
dz(1)=z(2);
dz(2)=Fx/m+u*w^2*cos(w*t)-k*z(1)/m-c*z(2)/m;
dz(3)=z(4);
dz(4)= Fy/m+u*w^2*sin(w*t)-k*(z(3)-z(5))/m-c*(z(4)-z(6))/m-g;        
dz(5)=z(6);
dx(6)= k*(z(3)-z(5))/M+c*(z(4)-z(6))/M-g-c3*z(6)/M-k3*z(3)/M;
这是松动与碰摩耦合故障的一个程序,主程序为z0=[0,1,0,1,0,1];
>> T=2*pi/2000;
>> options=odeset('RelTol',1e-5);
>> [t,z]=ode45('dafen9',[0:T/2048:1100*T],z0,options);
出现这样的错误提示??? Error using ==> c:/matlab6p5/toolbox/matlab/funfun/private/odearguments
DAFEN9 must return a column vector.
Error in ==> C:\MATLAB6p5\toolbox\matlab\funfun\ode45.m
On line 155  ==> [neq, tspan, ntspan, next, t0, tfinal, tdir, y0, f0, args, ...
请问什么原因

vib

最好把问题的物理背景介绍一下，大家不知道你的程序表达的含义，