求救！各位帮我看看我哪里做错了
这是我求桁架固有频率的程序 ，求不出结果，而且结构质量矩阵和刚度矩阵也不对，请各位帮我看看哪里出错了，谢谢！E=2.1e11;
A=1e-4;
density=7.3e3;
node_number=5;
element_number=7;
nc=;
en=;
ed(1:node_number,1:2)=1;
constraint=;
for loopi=1:length(constraint);
ed(constraint(loopi,1),constraint(loopi,2))=0;
end
dof=0;
for loopi=1:node_number
for loopj=1:2
if ed(loopi,loopj)~=0
dof=dof+1;
ed(loopi,loopj)=dof;
end
end
end
ek=E*A*;
em=(density*A)/2*eye(4);
k(1:dof,1:dof)=0;
m=k;
theta(1:7)=0;
el(1:7)=0;
e2s(1:4)=0;
for loopi=1:element_number
for zi=1:2
e2s((zi-1)*2+1)=ed(en(loopi,zi),1);
e2s((zi-1)*2+2)=ed(en(loopi,zi),1);
end
el(loopi)=sqrt((nc(en(loopi,1),1)-nc(en(loopi,2),1))^2+(nc(en(loopi,1),2)-nc(en(loopi,2),2))^2);
theta(loopi)=asin((nc(en(loopi,1),2)-nc(en(loopi,2),2))/el(loopi));
lmd=;
t=;
dk=t'*ek*t/el(loopi);
dm=t'*em*t*el(loopi);
for jx=1:4
for jy=1:4
if(e2s(jx)*e2s(jy)~=0)
k(e2s(jx),e2s(jy))=k(e2s(jx),e2s(jy))+dk(jx,jy);
m(e2s(jx),e2s(jy))=m(e2s(jx),e2s(jy))+dm(jx,jy);
end
end
end
end
=eig(k,m);
frequency=sqrt(diag(d))/(2*pi);
=sort(frequency);
d=d(:,indexf); {:3_60:}各位帮我看看吧~~~
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