SOL 106 and Computing Residual Stresses

[willindsey]

Hello,

I am working on a problem to model the autofrettage process for a metallic pressure vessel. An initial internal pressure is applied to yield the interior of pressure vessel and this is unloaded. What results is compressive residual stresses with in the vessel's walls. I've developed the nonlinear material model and verified it with tensile test results from literature, have been able to compute the stress state while under load, but have not been able to compute the compressive residual stresses following elastic recovery.

Is computing the residual stresses feasible with SOL 106?

Thanks,
William

 

[karachun]

Yes, you can use subcases. In SOL106 subcases are sequentially dependent so you create first subcase with your pressure load and then you create second subcase with some near zero load (you can not create zero load). You can copy your pressure load, change pressure to some neglectable value like 1e-6 Pa and use it for second subcase.
I recommend to practice on some simple example first. Create beam made from solid elements and load to plasticity/unload it with force. Be sure that you get some residual stresses and deformations and then proceed to your pressure vessel.

 

[willindsey]

Great! Thank you! It worked and got the solution I was looking for.