You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
75 lines
2.2 KiB
75 lines
2.2 KiB
4 years ago
|
%--------------------------
|
||
|
|
% @Author: Jingqiao Hu
|
||
|
|
% @Date: 2020-10-29 15:04:18
|
||
|
|
% @LastEditTime: 2021-01-12 15:09:02
|
||
|
|
%--------------------------
|
||
|
|
function [deform1, converged] = line_search(rhs, du, fext, deform0, ref_nodes, ...
|
||
|
|
dN_c, gradN, dF, edofMat, fixeddofs, lx, u, l, opt_rotation)
|
||
|
|
maxloop = 10; loop = 0;
|
||
|
|
nodeNum = size(deform0, 1);
|
||
|
|
deform0 = reshape(deform0', [], 1);
|
||
|
|
ref0 = reshape(ref_nodes', [], 1);
|
||
|
|
|
||
|
|
step = 1;
|
||
|
|
approxE0 = -sum(dot(rhs, deform0 - ref0));
|
||
|
|
norm0 = max(max(abs(rhs)));
|
||
|
|
found_step = 0;
|
||
|
|
|
||
|
|
while loop < maxloop
|
||
|
|
loop = loop+1;
|
||
|
|
|
||
|
|
deform1 = step*du + deform0;
|
||
|
|
deform2 = reshape(deform1,2,[])';
|
||
|
|
U = reshape(deform2' - ref_nodes', [], 1);
|
||
|
|
if opt_rotation
|
||
|
|
R = update_corotation_matrix(edofMat, U, dN_c);
|
||
|
|
[F, dF] = corotational_F(R, edofMat, ref_nodes, deform2, gradN);
|
||
|
|
else
|
||
|
|
F = deform_grad_1scale(edofMat, U, gradN); % {4}: 4*eleNum
|
||
|
|
end
|
||
|
|
% F = deform_gradient(eles, reshape(deform1,2,[])', ref_nodes, gradN); % {4*eleNum}: 2*2
|
||
|
|
|
||
|
|
inverted = check_inversion(F);
|
||
|
|
step = step*0.5;
|
||
|
|
if (inverted)
|
||
|
|
continue;
|
||
|
|
% regard as not converged,
|
||
|
|
% it is advised that the deformation gradient F be temporarily replaced by
|
||
|
|
% the nearest physically plausible value ~F
|
||
|
|
end
|
||
|
|
|
||
|
|
fint = elastic_force(F, dF, nodeNum, edofMat, lx, u, l);
|
||
|
|
rhs = fint + fext;
|
||
|
|
rhs(fixeddofs) = 0;
|
||
|
|
|
||
|
|
approxE1 = -sum(dot(rhs, deform1 - ref0));
|
||
|
|
norm1 = max(max(abs(rhs)));
|
||
|
|
if( (norm1<norm0) || (approxE1<approxE0) )
|
||
|
|
found_step=1;
|
||
|
|
break;
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
converged = 0;
|
||
|
|
if(~found_step || (abs(norm1-norm0)<1e-5))
|
||
|
|
converged = 1;
|
||
|
|
end
|
||
|
|
|
||
|
|
deform1(fixeddofs) = deform0(fixeddofs);
|
||
|
|
deform1 = reshape(deform1, 2, [])';
|
||
|
|
end
|
||
|
|
|
||
|
|
function inverted = check_inversion(F)
|
||
|
|
|
||
|
|
inverted = false;
|
||
|
|
eps = 1e-5;
|
||
|
|
|
||
|
|
for gp = 1:4
|
||
|
|
F1 = F{gp, 1}; % 4 * eleNum
|
||
|
|
Fdet = F1(1, :).*F1(4, :) - F1(2, :).*F1(3, :);
|
||
|
|
if (sum(Fdet <= eps) > 0)
|
||
|
|
inverted = true;
|
||
|
|
return;
|
||
|
|
end
|
||
|
|
end
|
||
|
|
end
|