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.

Young's Modulus as function of temperature

Please login with a confirmed email address before reporting spam

I am sure this should be easy, but I must be missing something simple...

Within a 3D stationary structural mechanics model, I have created an interpolation function to define the Young's Modulus as a function of Temperature at a few discrete temperature points. I have defined the interpolation function as shown in the attached image. I have then set the Young's Modulus within the material property to equal int1(Temp), where Temp is a global parameter I have created, again, shown in the attached image.

When I try to run the model, I get the error message:

"Unknown function or operator.
Name: int1
Feature: Stationary Solver 1 (sol1/s1)"

Any thoughts?

Thanks in advance!

Mark


5 Replies Last Post 2016年6月22日 GMT-4 02:13
Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 2016年6月21日 GMT-4 11:37
See if the suggestions here help:
www.comsol.com/community/forums/general/thread/116362/#p258731
If not, please consider posting your mph file - you can make it smaller by clearing the mesh and solutions if need be.
Jeff
See if the suggestions here help: https://www.comsol.com/community/forums/general/thread/116362/#p258731 If not, please consider posting your mph file - you can make it smaller by clearing the mesh and solutions if need be. Jeff

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 2016年6月21日 GMT-4 12:00
Fantastic, that was exactly what was needed. I had assumed that as there was only 1 component and 1 interpolation function in the model, it would be OK, but explicitly defining the function worked a treat. I have come across a (possible) bug though.

My model has 2 parameters that I sweep through, Temp[degC] and Pressure[psi]. The Titles in the chosen result seem to indicate incorrect units for the Temp parameter, as highlighted on the attached image. I have removed solutions/meshes and attached the model for your perusal.

Thanks so much for setting me straight, thought I was going mad!

regards,

Mark
Fantastic, that was exactly what was needed. I had assumed that as there was only 1 component and 1 interpolation function in the model, it would be OK, but explicitly defining the function worked a treat. I have come across a (possible) bug though. My model has 2 parameters that I sweep through, Temp[degC] and Pressure[psi]. The Titles in the chosen result seem to indicate incorrect units for the Temp parameter, as highlighted on the attached image. I have removed solutions/meshes and attached the model for your perusal. Thanks so much for setting me straight, thought I was going mad! regards, Mark


Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 2016年6月21日 GMT-4 14:25
Glad I could help.
That caption does look funny, indeed. I invite you to bring it to the attention of our support team: this is how we track incoming reports of possible bugs.
Thanks,
Jeff
Glad I could help. That caption does look funny, indeed. I invite you to bring it to the attention of our support team: this is how we track incoming reports of possible bugs. Thanks, Jeff

Jeff Hiller COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 2016年6月21日 GMT-4 14:48
Update: I was able to reproduce your screenshot in 5.2, but not in 5.2a, see my attached screenshot. It looks like this bug was crushed by our latest release.
Best,
Jeff
PS: Here is one more reason to upgrade from 5.2 to 5.2a: on my machine, your model solves about 6% faster with 5.2a than with 5.2.
Update: I was able to reproduce your screenshot in 5.2, but not in 5.2a, see my attached screenshot. It looks like this bug was crushed by our latest release. Best, Jeff PS: Here is one more reason to upgrade from 5.2 to 5.2a: on my machine, your model solves about 6% faster with 5.2a than with 5.2.


Please login with a confirmed email address before reporting spam

Posted: 8 years ago 2016年6月22日 GMT-4 02:13
Many thanks Jeff!

Looks like I should update ASAP...

Thanks again,

Mark
Many thanks Jeff! Looks like I should update ASAP... Thanks again, Mark

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.