function [sx,sy,sxy,s]=shear2d(md) %SHEAR2D - computes 2d strain rate % % This routine computes the strain rate of 2d models % % Usage: % [sx,sy,sxy,s]=shear2d(md); % s=shear2d(md); [alpha beta]=GetNodalFunctionsCoeff(md.mesh.elements,md.mesh.x,md.mesh.y); summation=[1;1;1]; sx=(md.initialization.vx(md.mesh.elements).*alpha)*summation; uy=(md.initialization.vx(md.mesh.elements).*beta)*summation; vx=(md.initialization.vy(md.mesh.elements).*alpha)*summation; sy=(md.initialization.vy(md.mesh.elements).*beta)*summation; sxy=(uy+vx)/2; s=sqrt(sx.^2+sy.^2+sxy.^2+sx.*sy); %if user requested only one output, it must be the norm if nargout==1, sx=s; end