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76 lines
2.2 KiB
76 lines
2.2 KiB
%--------------------------
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% @Author: Jingqiao Hu
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% @Date: 2020-11-28 21:26:00
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% @LastEditTime: 2021-01-12 15:10:03
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%--------------------------
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function [U1, converged] = line_search_linear(rhs, du, fext, U0, gradN, dF, edofMat, fixeddofs, lx, u, l)
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maxloop = 10; loop = 0;
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nodeNum = size(fext, 1) / 2;
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% deform0 = reshape(deform0', [], 1);
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% ref0 = reshape(ref_nodes', [], 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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% deform2 = reshape(deform1,2,[])';
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F = deform_grad_1scale(edofMat, U1, gradN);
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% if opt_rotation
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% U = reshape(deform2' - ref_nodes', [], 1);
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% R = update_corotation_matrix(edofMat, U, dN_c, deform2);
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% [F, dF] = corotational_F(R, edofMat, ref_nodes, deform2, gradN);
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% else
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% F = deform_gradient(eles, deform2, ref_nodes, gradN); % {4}: 4*eleNum
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% end
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% F = deform_gradient(eles, reshape(deform1,2,[])', ref_nodes, gradN); % {4*eleNum}: 2*2
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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, dF, nodeNum, 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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% deform1 = reshape(deform1, 2, [])';
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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 = 1:4
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F1 = F{gp, 1}; % 4 * eleNum
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Fdet = F1(1, :).*F1(4, :) - F1(2, :).*F1(3, :);
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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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