ABAQUS 6.8, buckling, intermediate axial load 1

[nuh]

hi everyone,
____________________________________________
| -->|cross section of |<-- |
|annular -->|solid circular plate |<-- annular |
|________-->|____________________|<--________|
figure:cross section of the circular plate with annular plate
<-- is the load

I am trying to model (in ABAQUS 6.8) a solid circular plate with an annular plate attached to it (the inner radius = solid circular plate radius) and run a buckling analysis for load applied at the edge of the solid circular plate.
The structure is clamped at outer radius (I constrained all possible displacement).
TIE constraint is used to 'glued' the solid circular plate to the inner edge of the annular plate.

I tried to model using CAX (axisymmetric element), SOLID element and SHELL element. However all results did not agreed with the analytical result. Hope there are peoples can help me here...

Thank you.

N.A.S

 

[corus]

With buckling analyses the mode shapes may not all be axisymmetric as you have assumed in your model. You may have to model a segment of the plates.

corus

 

[nuh]

Thank you for your respond.

Yes, indeed I made just a segment for model SOLID elements which gave similar results to the model with axisymmetric (CAX) elements. While for model with SHELL elements I did for full circular plate which include every possible modes.
However, the problem is the critical buckling load (the first buckling mode) given by ABAQUS does not agreed with the analytical results reported in some article. The mode shape given by the ABAQUS for the first mode is indeed an axisymmetric one but the magnitude disagree with the analytical results.
For your information, I have tried to run the analysis with the load is at the outer edge (or in other words, the problem should be the buckling of simple solid circular plate) and the analysis went successfully.

Additional information that I forgot in my last post, is the annular plate and the solid circular plate having the same alloy properties.

Hope that explain a little bit more on my situations.

N.A.S

 

[kellnerp]

the analytical results reported in some article

Can you tell us what this article is? Your question is too general to give a specific answer.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."

 

[nuh]

It is an article by T. M. Aung and C.M. Wang titled as "Buckling of circular plates under intermediate and edge radial loads". It was published in Thin-Walled Structures, Volume 43, Issue 12, December 2005, Pages 1926-1933.
The problem that I tried to model is circular plate applied with intermediate radial load without the edge radial load.

Hope that information will give more clear idea on the problems that I am working on.

N.A.S

 

[kellnerp]

I'm not familiar with that article.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."

 

[fea4mil]

You can use Fourier method instead of a complete 3-D approach in order to perform (linear and non linear) multi-harmonic analyses of axisymmetric structures, under any load case and taking into account if any coupling between different harmonics. This method is particularly suited to the buckling of cylindrical shallow shells.
Fea4miL