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 The information provided may be out of date.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.

Analytic function - Failed to find consistent initial values

Please login with a confirmed email address before reporting spam

Hi,

I'm running this coupled heat transfer-structural model where the Young modulus (E) is a function of temperature (T), so it's a one way coupling. The analysis is time dependent. I define the relation between E and T using an analytic function (so called myYM) in "Materials" as a simple power law:

24.2+5.6*T^1.45

I define two time-dependent steps in my "Study", first one only solving for heat transfer physics and the next one for the solid mechanics physics. I tried both Segragated and Fully coupled solvers (with direct and iterative options), but each time I get the following error:

- Failed to find consistent initial values
Error in user-defined function.
Function: mod1.mat1.def.myYM

Strangely enough, when I change the analytic function to a linear equation, i.e. 24.2+5.6*T, the problem is solved! So I guess there is a problem with derivative of analytic function. I also tried to give the derivative manually, but it didn't work either.

Does anyone know how to work around this problem?

0 Replies Last Post Mar 31, 2011, 5:17 a.m. EDT
COMSOL Moderator

Hello Ali Reza

Your Discussion has gone 30 days without a reply. If you still need help with COMSOL and have an on-subscription license, please visit our Support Center for help.

If you do not hold an on-subscription license, you may find an answer in another Discussion or in the Knowledge Base.

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.