Type of Mesh for Elastic-Plastic analysis

[Alpete1430]

Hi all,
I'm trying to perform an Elastic-Plastic analysis to one of the systems which goes into Oil and Gas field.
It is governed by API 6A and ASME Sec VIII Div 2 'Design by analysis'.
My question is, which type of elements are good for this study and why?

Currently I'm performing an analysis with 2nd order Tet mesh and after some loading the elements are getting distorted.
So, if I mesh the system with 2nd order Hex mesh, will the results change?

What is the general practice across industry when it comes to what type of mesh to use in Elastic-Plastic analysis?

Thanks in advance.
Alpete1430

 

[Erik Panos Kostson]

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