用MATLAB做tpms模型中的有厚度gyroid结构，并且定义所有自定义函数且输出inp文件

以下是一个可能的实现代码，包括定义函数、生成三维网格、定义有限元、定义有限元方程、解决有限元方程和输出inp文件：

% 定义函数，计算有厚度gyroid结构
function [u,v,w] = gyroid_with_thickness(x,y,z,t)
    r = sqrt(x^2+y^2+z^2);
    u = sin(x)*cos(y) + sin(y)*cos(z) + sin(z)*cos(x) + t*sin(r);
    v = sin(x)*cos(z) + sin(y)*cos(x) + sin(z)*cos(y) + t*sin(r);
    w = sin(y)*cos(x) + sin(z)*cos(y) + sin(x)*cos(z) + t*sin(r);
end

% 定义常量和变量
xmin = -1; xmax = 1;
ymin = -1; ymax = 1;
zmin = -1; zmax = 1;
nx = 20; ny = 20; nz = 20;
ne = (nx-1)*(ny-1)*(nz-1);
thickness = 0.1;

% 生成三维网格
[x,y,z] = meshgrid(linspace(xmin,xmax,nx),linspace(ymin,ymax,ny),linspace(zmin,zmax,nz));

% 定义有限元
pde = struct('msh',[],'coeffs',[],'fea',[]);
pde.msh = struct('x',x(:),'y',y(:),'z',z(:),'e',delaunay(x(:),y(:),z(:)));
pde.fea = struct('u',[],'v',[],'w',[]);
pde.fea.u = zeros(size(x));
pde.fea.v = zeros(size(x));
pde.fea.w = zeros(size(x));

% 定义有限元方程
pde.coeffs = struct('a',[],'b',[],'c',[],'d',[],'e',[],'f',[]);
pde.coeffs.a = @(region,state) 1;
pde.coeffs.b = @(region,state) 0;
pde.coeffs.c = @(region,state) 1;
pde.coeffs.d = @(region,state) 0;
pde.coeffs.e = @(region,state) 1;
pde.coeffs.f = @(region,state) gyroid_with_thickness(state.x,state.y,state.z,thickness);

% 解决有限元方程
fea = parabolic(pde,'tlist',1);

% 输出inp文件
fid = fopen('gyroid_with_thickness.inp','w');
fprintf(fid,'*NODE, NSET=NALL\n');
for i = 1:numel(x)
    fprintf(fid,'%d, %f, %f, %f\n',i,x(i),y(i),z(i));
end
fprintf(fid,'*ELEMENT, TYPE=C3D8R, ELSET=EALL\n');
for i = 1:ne
    n1 = pde.msh.e(i,1);
    n2 = pde.msh.e(i,2);
    n3 = pde.msh.e(i,3);
    n4 = pde.msh.e(i,4);
    n5 = pde.msh.e(i,5);
    n6 = pde.msh.e(i,6);
    n7 = pde.msh.e(i,7);
    n8 = pde.msh.e(i,8);
    fprintf(fid,'%d, %d, %d, %d, %d, %d, %d, %d, %d\n',i,n1,n2,n3,n4,n5,n6,n7,n8);
end
fprintf(fid,'*ELASTIC\n');
fprintf(fid,'1.0E+07,0.3\n');
fprintf(fid,'*DENSITY\n');
fprintf(fid,'1.0\n');
fprintf(fid,'*THERMAL\n');
fprintf(fid,'1.0,0.0\n');
fprintf(fid,'*STEP\n');
fprintf(fid,'*STATIC\n');
fprintf(fid,'1.0,1.0,1.0E-04,1.0E-04\n');
fprintf(fid,'*BOUNDARY\n');
fprintf(fid,'NFACE1,1,6\n');
fprintf(fid,'NFACE2,2,5\n');
fprintf(fid,'NFACE3,3,4\n');
fprintf(fid,'NFACE4,1,2\n');
fprintf(fid,'NFACE5,3,6\n');
fprintf(fid,'NFACE6,4,5\n');
fprintf(fid,'*INITIAL CONDITIONS, TYPE=TEMPERATURE\n');
for i = 1:numel(x)
    fprintf(fid,'%d, %f\n',i,0);
end
fprintf(fid,'*STEP\n');
fprintf(fid,'*HEAT TRANSFER, DELTMX=1.0, RTOL=1.0E-06\n');
fprintf(fid,'1.0,1.0,1.0E-04,1.0E-04\n');
fprintf(fid,'*NODE FILE\n');
fprintf(fid,'U, TEMP\n');
for i = 1:numel(x)
    fprintf(fid,'%d, %f, %f\n',i,fea.sol.u(i),fea.sol.T(i));
end
fclose(fid);

这段代码可能还需要进行调试和修改，具体实现细节还需要参考相关文献和实际情况进行调整。