function AssembleStiffnessMatrix( ie, k )
%  把单元刚度矩阵集成到整体刚度矩阵
%  输入参数:
%      ie  --- 单元号
%      k   --- 单元刚度矩阵
%  返回值:
%      无
    global gElement gK
    for i=1:1:3
        for j=1:1:3
            for p=1:1:2
                for q=1:1:2
                    m = (i-1)*2+p ;
                    n = (j-1)*2+q ;
                    M = (gElement(ie,i)-1)*2+p ;
                    N = (gElement(ie,j)-1)*2+q ;
                    gK(M,N) = gK(M,N) + k(m,n) ;
                end
            end
        end
    end
return