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3D Thermal expansion

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Hello,

I'm looking for a solution to model the thermal stresses on a thermal cutoff with Comsol 3.5. The geometry is a cuboid.
First I only modeled the transient Joule Heating wihtout stresses. And the results coincide with the ones from a pre-existing model: there is an ingoing current varying with time on the left end and a zero potential condition on the right side. The remaining boundarys are insulated. The left and right side also have a boundary condition of a constant temperature and the remaining bounds are insulated as well.

No in order to analyse the thermal strain on the cutoff, i added Structural Mechanics Module ->Solid, Stress-Strain -> transient.
Then in the subdomain equations, I added the expression :
"+E_sld*alpha*Tt/(1-2*nu_sld)"
to all three normal stresses (sx_sld, sy_sld, sz_sld) to couple the Temperature to the stresses (I don't have the proper comsol multiphysics model for that).

Now I'm not sure about these equations
The only constraints are set on the left and right boundary (Rx=Ry=Rz=0).

My resulting stresses are in the same order of magnitude as in the existing model, but the deformation seems to be significantly smaller.
Do I need to male a different or additional coupling within the equation system?
I don't have access to the file right now, but I could add it at a later time.
Any help or suggestions would be appreciated.

Eva

0 Replies Last Post May 19, 2010, 3:59 p.m. EDT
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