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Post-buckling study
Posted 7 mars 2016, 14:40 UTC−5 Acoustics & Vibrations, Structural Mechanics Version 4.4, Version 5.1 3 Replies
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Hi all,
I was working on post buckling study. The geometry is a cylinder with internal mass connected by beams, the buckling point should be when the internal mass start to rotate(so the beams buckled)
I have two questions with it now
1. What is the most important thing I need to define in the solver to make sure the continuation.
2. For the stop condition, what variable can I define to express the internal mass rotation. I tried to use displacement of a point on beam, but it shows error that the solution is not converged.
Anyone can help me with it?
Thanks!!!
I was working on post buckling study. The geometry is a cylinder with internal mass connected by beams, the buckling point should be when the internal mass start to rotate(so the beams buckled)
I have two questions with it now
1. What is the most important thing I need to define in the solver to make sure the continuation.
2. For the stop condition, what variable can I define to express the internal mass rotation. I tried to use displacement of a point on beam, but it shows error that the solution is not converged.
Anyone can help me with it?
Thanks!!!
3 Replies Last Post 9 mars 2016, 12:12 UTC−5
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Posted:
8 years ago
Hi,
Start by taking a look at this model
www.comsol.com/model/postbuckling-analysis-of-a-hinged-cylindrical-shell-10257
where you can see how to set up the Continuation solver.
It is also discussed in this blog post:
www.comsol.se/blogs/buckling-structures-suddenly-collapse/
The stop condition is not necessary. It just reduces the computation time since you do not need to spend a lot of iterations far out in the nonlinear regime. It will not in itself be the cause of non-convergence.
Regards,
Henrik
Start by taking a look at this model
www.comsol.com/model/postbuckling-analysis-of-a-hinged-cylindrical-shell-10257
where you can see how to set up the Continuation solver.
It is also discussed in this blog post:
www.comsol.se/blogs/buckling-structures-suddenly-collapse/
The stop condition is not necessary. It just reduces the computation time since you do not need to spend a lot of iterations far out in the nonlinear regime. It will not in itself be the cause of non-convergence.
Regards,
Henrik
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Posted:
8 years ago
Hi,
Thank you for your help.
The model you mentioned is what I practiced with. But what I found in the solver is the stop condition and clear the reaction force check box. Doing the later one didn't show me anything interesting in my model. That's why I started to think about the stop condition.
Did I miss anything that might relative to the continuation solver?
Many thanks.
Thank you for your help.
The model you mentioned is what I practiced with. But what I found in the solver is the stop condition and clear the reaction force check box. Doing the later one didn't show me anything interesting in my model. That's why I started to think about the stop condition.
Did I miss anything that might relative to the continuation solver?
Many thanks.
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Posted:
8 years ago
By the way, the load applied to the model is a displacement normal to the cylinder. I defined the sweep parameter as the displacement. To show the results, I did a 1-D plot for a point on one of those beams, point displacement vs. displacement applied on the model. But it just show me a linear line.