45 lines
1.2 KiB
Mathematica
45 lines
1.2 KiB
Mathematica
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function[M]=MassMatrix(material,mesh,quadrature,ShapeOption)
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M=zeros(mesh.nn*3);
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I=[material.t 0 0 %w
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0 material.t^3/12 0 %dw/dx ת<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>*<EFBFBD>Ǽ<EFBFBD><EFBFBD>ٶ<EFBFBD>
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0 0 material.t^3/12];%dw/dy
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if strcmp(ShapeOption,'Q4')
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shape_order=4;
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elseif strcmp(ShapeOption,'Q8')
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shape_order=8;
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elseif strcmp(ShapeOption,'Q9')
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shape_order=9;
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end
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for iel=1:mesh.ne
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MElem=zeros(shape_order*3);
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for ig=1:size(quadrature.points,1)
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shapeFunction=ShapeFunction(quadrature.points(ig,1),quadrature.points(ig,2),ShapeOption);
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elemCoordinates=[mesh.Nid(mesh.Eid(iel,2:end),2), mesh.Nid(mesh.Eid(iel,2:end),3)];
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jacobian=Jacobian(shapeFunction,elemCoordinates);
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N=zeros(3,shape_order*3);
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for ib=1:shape_order
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temp=[shapeFunction.fun(ib) 0 0
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0 shapeFunction.fun(ib) 0
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0 0 shapeFunction.fun(ib)];
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N(:,ib*3-2:ib*3)=temp;
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end
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MElem=MElem+quadrature.weights(ig)*(material.rho*N'*I*N)*det(jacobian.matrix);
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end
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ntot=mesh.Eid(iel,2:end)*3-2;
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for j=1:numel(ntot)
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for k=1:numel(ntot)
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M(ntot(j):ntot(j)+2,ntot(k):ntot(k)+2) = M(ntot(j):ntot(j)+2,ntot(k):ntot(k)+2) + MElem(j*3-2:j*3,k*3-2:k*3);
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end
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end
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end
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return
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