function K = BeamAssemble(K,k,i,j)
% BeamAssemble

I = 2*i-1:2*i;
J = 2*j-1:2*j;

K(I,I) = K(I,I) + k(1:2,1:2);
K(J,I) = K(J,I) + k(3:4,1:2);
K(J,J) = K(J,J) + k(3:4,3:4);
K(I,J) = K(I,J) + k(1:2,3:4);

endfunction