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64 lines
1.5 KiB
64 lines
1.5 KiB
3 years ago
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%--------------------------
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% @Author: Jingqiao Hu
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% @Date: 2020-11-28 21:26:00
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% @LastEditTime: 2021-02-28 18:45:51
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%--------------------------
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function [U1, converged] = line_search_linear(rhs, du, U0, fext, dN, edofMat, fixeddofs, lx, u, l)
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maxloop = 10; loop = 0;
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alldofs = size(fext, 1);
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step = 1;
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approxE0 = -sum(dot(rhs, U0));
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norm0 = max(max(abs(rhs)));
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found_step = 0;
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while loop < maxloop
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loop = loop+1;
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U1 = step*du + U0;
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F = deform_grad(dN, edofMat, U1);
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inverted = check_inversion(F);
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step = step*0.5;
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if (inverted)
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continue;
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% regard as not converged,
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% it is advised that the deformation gradient F be temporarily replaced by
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% the nearest physically plausible value ~F
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end
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fint = elastic_force_linear(F, dN, alldofs, edofMat, lx, u, l);
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rhs = fint + fext;
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rhs(fixeddofs) = 0;
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approxE1 = -sum(dot(rhs, U1));
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norm1 = max(max(abs(rhs)));
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if( (norm1<norm0) || (approxE1<approxE0) )
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found_step=1;
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break;
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end
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end
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converged = 0;
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if(~found_step || (abs(norm1-norm0)<1e-5))
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converged = 1;
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end
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U1(fixeddofs) = U0(fixeddofs);
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end
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function inverted = check_inversion(F)
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inverted = false;
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eps = 1e-5;
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for gp = 1:8
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F1 = F{gp, 1}; % 9 * eleNum
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Fdet = det_3rank(F1);
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if (sum(Fdet <= eps) > 0)
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inverted = true;
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return;
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end
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end
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end
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