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 The information provided may be out of date.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.

About linear buckling mode.

Please login with a confirmed email address before reporting spam

Hi, all

I'm wondering whether 'Linear Buckling' is working correctly.

In 2D, for example,

rectangle(GaAs) 23um X 0.1um with fixed two boundaries(0.1um) is placed.

And I gave +-400000000N/m as an compressive force per length to the fixed boundaries.

Also, perturbation is included.

I think compressive force per length is sufficiently large to make buckling mode.

However, It does gives a lot of warning and defected result, regardless of mode n=1,2,3.....

Not to speak of complex 2D model or 3D one.

I think that sine-shape result must be given.


What is the problem? Is there any program defect about Linear Buckling in COMSOL?



Thank you.

1 Reply Last Post 2 mars 2012, 09:09 UTC−5
COMSOL Moderator

Hello Byeong Gyun Oh

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 2 mars 2012, 09:09 UTC−5
Hello,

I am not sure if this answer is still needed, but there is a basic problem here. If my understanding is correct, you are applying stress on a fixed support. This is incorrect, since since you cannot have both on the same boundary. Instead, try to impose an internal body stress of the same amount. I would first try to do a static calculation with no buckling analysis with very low stress, just to see if the model is correct. Then after that, do the buckling.
doni
Hello, I am not sure if this answer is still needed, but there is a basic problem here. If my understanding is correct, you are applying stress on a fixed support. This is incorrect, since since you cannot have both on the same boundary. Instead, try to impose an internal body stress of the same amount. I would first try to do a static calculation with no buckling analysis with very low stress, just to see if the model is correct. Then after that, do the buckling. doni

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.