Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

How to cause calculated strains from PDE for constitutive model

Please login with a confirmed email address before reporting spam

Hi everybody!

I have a quick question for you about implementation own constitutive model.

So my model describe shotcrete behaviour and it’s composed from several parts responsible for shrinkage, reversible creep, elastic behaviour which depend on current stress level etc.
I have used PDE to calculate strain and it works very well, to include elastic modulus which depend on the current stress level I used the stress from linear elastic model.

My question is how to cause these calculated strains in the model? Let say that I have values of scalars for each local direction. Is it good solution just to replace normal equations for linear elastic model under “equation view”? or there is better solution for it?

Thank you in advance for help!

1 Reply Last Post 17 lug 2013, 18:40 GMT-4

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 17 lug 2013, 18:40 GMT-4
Hi,


Some time ago when I had no structural mechanics module, and just linear elasticity, I had to solve a time dependent thermo-elastic problem.

In order to include thermal strain, I had then directly modified the stresses S11, S22 and S33 in linear elasticity equation view by appending to the existing equations an extra term -3.0*thermal_exp_coeff*(T-Tr)*solid.K in S11, 22 and 33 and clicked on 'Refresh equations'. I had got good comparison with an alternative code.

If this is what you meant.


Suresh
Hi, Some time ago when I had no structural mechanics module, and just linear elasticity, I had to solve a time dependent thermo-elastic problem. In order to include thermal strain, I had then directly modified the stresses S11, S22 and S33 in linear elasticity equation view by appending to the existing equations an extra term -3.0*thermal_exp_coeff*(T-Tr)*solid.K in S11, 22 and 33 and clicked on 'Refresh equations'. I had got good comparison with an alternative code. If this is what you meant. Suresh

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.