I am attempting to determine the Von Mises Stresses that occur in a long tunsten tube when applied to a thermal load. I don't know if it is because of the matieral properties of Tungsten coupled with the thin walls of the tube, or if it is something I am during incorrectly in my code, but everytime I solve the structural model given the results of the thermal model, I get ZERO STRESSES. Not even small numbers...ZERO.
Here is my code:
tmodel = createpde('thermal','transient');
D = 2.5;
thick = 0.125;
rin = D/2;
rout = rin + thick;
L = 1318;
gm = multicylinder([rin,rout],L,'void',[1,0]);
msh = generateMesh(tmodel,'Hmax',0.5);
SHfun =@(location,state) (21.868372 + 8.068661e-3*state.u - 3.756196e-6*state.u.^2 + 1.075862e-9*state.u.^3 + (1.406637e4./state.u.^2))./183.84;
TCfun =@(loaction,state) (149.441 - 45.466e-3*state.u + 13.193e-6*state.u.^2 - 1.484e-9*state.u.^3 + (3.866e6./state.u.^2))./1000;
MDfun =@(location,state) (19.25 - 2.66207e-4*(state.u - 293.15) - 3.0595e-9*(state.u - 293.15).^2 - 9.5185e-12*(state.u - 293.15).^3)./1000;
T0_fun =@(location) location.z.^2
tlist = [0 0.1]
Tresults = solve(tmodel,tlist);
The point of the code up to this point is to get the thermal profile that I want to apply to my structural model into the proper PDE format of Tresults. Now that that is down, I apply it to the Structural model.
smodel = createpde('structural','static-solid');
smodel.Mesh = msh;
Unfortunatly it doesn't allow the Young's Modulus to change with Temperature.
I have also tried apply the results of all Timesteps.
structuralBC(smodel,'Face',[1 3 4],'Constraint','fixed')
Sresults = solve(smodel);
Running this yeilds ZERO STRESS. I have also tried a similar Axis-Symmetric model with the same results of ZERO STRESS.
The only time I get any STRESS results is when I apply a Pressure load:
Does anyone have any idea why I am not getting any Thermal STRESS?