Abaqus riks

[ohdk]

Hello
I am using abaqus riks to represent a behavior of honeycomb structure under compression
I want to compress half of the total length of the structure for example I gave displacement 10, total height of honeycomb structure is 20. It is not simple honeycomb structure so I imported geometry. It is 3D solid. I used tetrahedral meshes.
I assume there will be a buckling so I used Riks method but the problem is maximum displacement I got is only 3 but I want to see this strcuture collapse more. Even though I increased displacement, it still converges to the displacement 3.
When I visulize this, I could see in the beginning of increment steps, it is really compressed but it stabilize at some points during rest of steps.

My question is that how can I make this strcuture compress more with larger displacement.

Thank you

 

[IceBreakerSours]

I am not a structural engineer so I may be wrong but if you prescribed a displacement BC, then why would the structure buckle?

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[ohdk]

Okay.. I prescribed a displacement on the top surface of the honeycomb structure and a displacement is pretty big enough to buckle, a displamcent is 50% of total height of the stucture

 

[IceBreakerSours]

I feel fairly confident in saying that you need to read about buckling carefully. Here is one resource:

http://www.continuummechanics.org/cm/columnbuckling.html

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[ohdk]

No. I am sure you did not understand what I am asking. It already started to buckle in a small displacement. What I want to know is that simulation is not converging to the displacement I gave.

 

[IceBreakerSours]

Yes, you may be right in the sense I do not understand how something can *buckle* when *displacement* has been *prescribed* instead of a *load*. But I am no structural engineer so there's that. Or, may be I haven't understood what the 'real' question/issue is.

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[IceBreakerSours]

Read the first line of this blog (by one of the famous FE experts):

http://www.deskeng.com/de/linear-and-nonlinear-buckling-in-fea/

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