随便写写之poisson方程

 E0=[2 -1/2 0 0;-1/2 4 -1/2 0;0 -1/2 4 -1/2;0 0 -1/2 4];
E1=[7/2 -1/2 0 0;-1/2 8 -1/2 0;0 -1/2 8 -1/2;0 0 -1/2 8];
K=[-3/2 0 0 0;0 -3 0 0;0 0 -3 0;0 0 0 -3];
Z=zeros(4);

EE=[E0 K Z Z Z;K 2*E0 K Z Z;Z K 2*E0 K Z;Z Z K 2*E0 K;Z Z Z K E0];

mE0=[-50 25 0 0 0 0;25 -100 25 0 0 0;0 25 -100 25 0 0;0 0 25 -100 25 0;0 0 0 25 -100 25;0 0 0 0 25 -100];
%mE1=[7/2 -1/2 0 0;-1/2 8 -1/2 0;0 -1/2 8 -1/2;0 0 -1/2 8];
mK=diag([25 50 50 50 50 25]);
mZ=zeros(6);

EEE=[mE0 mK mZ mZ mZ mZ;mK 2*mE0 mK mZ mZ mZ;mZ mK 2*mE0 mK mZ mZ;mZ mZ mK 2*mE0 mK mZ;mZ mZ mZ mK 2*mE0 mK;mZ mZ mZ mZ mK 2*mE0]