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About linear buckling mode.

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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 mar 2012, 09:09 GMT-5
COMSOL Moderator

Hello Byeong Gyun Oh

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Posted: 1 decade ago 2 mar 2012, 09:09 GMT-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

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