XIAN-FEM-2026June/三维matlab代码/matlab 3D一阶本征问题/3D一阶本征问题2/assembly_equ.m

77 lines
1.9 KiB
Matlab

function solver=assembly_equ(phy,mesh,solver)
solver.Dof=mesh.NbrEdge;
%四面体积分节点
[u,v,w,weight,nbrGP]=getGaussPoints(1);
Ai=zeros(mesh.NbrTet*36,1);
Aj=zeros(mesh.NbrTet*36,1);
Av=zeros(mesh.NbrTet*36,1);
Bi=zeros(mesh.NbrTet*36,1);
Bj=zeros(mesh.NbrTet*36,1);
Bv=zeros(mesh.NbrTet*36,1);
for n=1:mesh.NbrTet
%vertex
x=mesh.Vertex(mesh.Tet(n,:),1);
y=mesh.Vertex(mesh.Tet(n,:),2);
z=mesh.Vertex(mesh.Tet(n,:),3);
%jac
Jac=zeros(3,3);
Jac(1,1)=x(1)-x(4);Jac(1,2)=y(1)-y(4);Jac(1,3)=z(1)-z(4);
Jac(2,1)=x(2)-x(4);Jac(2,2)=y(2)-y(4);Jac(2,3)=z(2)-z(4);
Jac(3,1)=x(3)-x(4);Jac(3,2)=y(3)-y(4);Jac(3,3)=z(3)-z(4);
DetJac=abs(det(Jac));
TJac=Jac'/det(Jac);
%BF
E=zeros(3,6,nbrGP);curlE=zeros(3,6,nbrGP);
for i=1:nbrGP
for j=1:6
E(:,j,i)=getBF(1,j,u(i),v(i),w(i));
E(:,j,i)=Jac\E(:,j,i);
curlE(:,j,i)=getBF(2,j,u(i),v(i),w(i));
curlE(:,j,i)=TJac*curlE(:,j,i);
end
end
%matrix
mur=phy.mur(mesh.DomainOfTet(n));
eps=phy.eps(mesh.DomainOfTet(n));
%submatrix
Ae=zeros(6,6);
Be=zeros(6,6);
for i=1:6
for j=1:6
for k=1:nbrGP
Ae(i,j)=Ae(i,j)+weight(k)*DetJac*sum(curlE(:,i,k).*curlE(:,j,k));
Be(i,j)=Be(i,j)+weight(k)*DetJac*eps*sum(E(:,i,k).*E(:,j,k));
end
end
end
%put in matrix
for i=1:6
for j=1:6
index=(n-1)*36+(i-1)*6+j;
Ai(index)=mesh.EdgeOfTet(n,i);
Aj(index)=mesh.EdgeOfTet(n,j);
Av(index)=Ae(i,j);
Bi(index)=mesh.EdgeOfTet(n,i);
Bj(index)=mesh.EdgeOfTet(n,j);
Bv(index)=Be(i,j);
end
end
end
solver.Ai=[solver.Ai;Ai];
solver.Aj=[solver.Aj;Aj];
solver.Av=[solver.Av;Av];
solver.Bi=[solver.Bi;Bi];
solver.Bj=[solver.Bj;Bj];
solver.Bv=[solver.Bv;Bv];
end