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 The information provided may be out of date.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 apply initial stress

Please login with a confirmed email address before reporting spam

Hi!

I made a model of a string with initial stress using a truss element and I obtained exactly the same eigenfrequencys than manually using theorical formulas.
Now I want to make the model using a beam element, but I get totally different results. Moreover, changing the value of the initial stress, the eigenfrequency doesn`t vary, wich is no correct.

So, wich is the problem?

Thanks,

Bruno.

2 Replies Last Post 06.07.2012, 13:18 GMT-4
COMSOL Moderator

Hello Bruno Rango

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.


Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 06.07.2012, 04:53 GMT-4
I have absolutely similar problem.
Is there any standard solution to define the pre-stress in the uni-/bimorph structures?

Somehow it is routine task, to look for the eigenfrequencies modified by the technology-induced
strain/stress variations.

I will be very thankfull for the advice from someone solved the problem.
At the moment I am using analytical formulas for simple bridges, but for mor complex geometries
it does not work of course.
I have absolutely similar problem. Is there any standard solution to define the pre-stress in the uni-/bimorph structures? Somehow it is routine task, to look for the eigenfrequencies modified by the technology-induced strain/stress variations. I will be very thankfull for the advice from someone solved the problem. At the moment I am using analytical formulas for simple bridges, but for mor complex geometries it does not work of course.

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 06.07.2012, 13:18 GMT-4
Hi

"my way" is to apply a stationary solver case first and use that as intial conditions (with or without remeshing, all depends)

--
Good luck
Ivar
Hi "my way" is to apply a stationary solver case first and use that as intial conditions (with or without remeshing, all depends) -- Good luck Ivar

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.