function [kinmtpb]=sbB(nnel,dhdx,dhdy)

%--------------------------------------------------------------------------
%  目的:
%     計(jì)算彎曲幾何函數(shù)矩陣
%
%  
%  變量:
%     nnel - 每個(gè)單元節(jié)點(diǎn)數(shù)
%     dhdx - 形函數(shù)對迪卡爾坐標(biāo)x的求導(dǎo)
%     dhdy - 形函數(shù)對迪卡爾坐標(biāo)y的求導(dǎo)
%--------------------------------------------------------------------------

 for i=1:nnel
 i1=(i-1)*3+1;  
 i2=i1+1;
 i3=i2+1;
 kinmtpb(1,i1)=dhdx(i);
 kinmtpb(2,i2)=dhdy(i);
 kinmtpb(3,i1)=dhdy(i);
 kinmtpb(3,i2)=dhdx(i);
 kinmtpb(3,i3)=0;
 end