27 lines
1.1 KiB
Mathematica
27 lines
1.1 KiB
Mathematica
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function [Kt,Elem] = tangStiffMtxUL(Model,Anl,Elem,U)
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%<EFBFBD><EFBFBD><EFBFBD><EFBFBD>λ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>½ڵ<EFBFBD>λ<EFBFBD>ú<EFBFBD><EFBFBD>õ<EFBFBD><EFBFBD>ĵ<EFBFBD>Ԫ<EFBFBD>նȾ<EFBFBD><EFBFBD><EFBFBD>
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Kt = zeros(Model.neq,Model.neq);
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for i = 1:Model.nel
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% Elastic, geometric and tangent stiffness matrices
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ke = elasticStiffMtxUL(Elem(i),U);%UӰ<EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӱ<EFBFBD>쵥Ԫ<EFBFBD><EFBFBD><EFBFBD><EFBFBD>
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kg = geometricStiffMtxUL(Anl,Elem(i),U);
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kt = ke + kg;
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% Store elastic stiffness matrix to be used in computation of internal forces
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Elem(i).ke = ke;
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% Rotation matrix from local to global coordinate system
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angle = elemAngle(Elem(i),U);%%UӰ<EFBFBD><EFBFBD><EFBFBD>ڵ<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ӱ<EFBFBD>쵥Ԫ<EFBFBD>Ƕ<EFBFBD>
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c = cos(angle);
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s = sin(angle);
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rot = [ c -s 0 0 0 0;
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s c 0 0 0 0;
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0 0 1 0 0 0;
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0 0 0 c -s 0;
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0 0 0 s c 0;
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0 0 0 0 0 1 ];
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% Tangent stiffness matrix in global system
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k = rot * kt * rot';
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% Assemble element matrix to global matrix
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gle = Elem(i).gle;
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Kt(gle,gle) = Kt(gle,gle) + k;
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end
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end
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