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.
37 lines
995 B
37 lines
995 B
3 years ago
|
%--------------------------
|
||
|
|
% @Author: Jingqiao Hu
|
||
|
|
% @Date: 2020-11-28 21:07:50
|
||
|
|
% @LastEditTime: 2020-11-28 21:49:42
|
||
|
|
%--------------------------
|
||
|
|
function f = elastic_force_linear(F, dF, nodeNum, edofMat, lx, u, l)
|
||
|
|
|
||
|
|
f = zeros(nodeNum*2, 1);
|
||
|
|
jac = lx^2/4;
|
||
|
|
eleNum = size(edofMat,1);
|
||
|
|
|
||
|
|
for gp = 1:4
|
||
|
|
dFe = dF{gp}; % 4 * 8 * m
|
||
|
|
Fe = F{gp, 1}; % 4 * m
|
||
|
|
P2(1, :, :) = PK1_fast_linear(u, l, Fe); % 4 * m
|
||
|
|
|
||
|
|
fe = squeeze(mtimesx(P2, dFe)) * jac; % 8*m
|
||
|
|
|
||
|
|
for ele = 1:eleNum
|
||
|
|
edof = edofMat(ele, :);
|
||
|
|
f(edof) = f(edof) - fe(:, ele); % NOTE: MINUS!
|
||
|
|
end
|
||
|
|
end
|
||
|
|
end
|
||
|
|
|
||
|
|
% I = eye(2,2);
|
||
|
|
% PP = u*(F + F'-2*I) + l * trace(F-I) * I;
|
||
|
|
function P = PK1_fast_linear(u, l, F)
|
||
|
|
m = size(F,2);
|
||
|
|
|
||
|
|
FT = F([1,3,2,4], :); % 4*m
|
||
|
|
trF = F(1,:) + F(4,:) - 2; % 1*m
|
||
|
|
|
||
|
|
I = repmat([1;0;0;1], 1, m); % 4*m
|
||
|
|
|
||
|
|
P = u(:)' .* (F + FT - 2*I) + l(:)' .* trF .* I;
|
||
|
|
end
|