Ansys displacement calculation

[Vitkacy1989]

Hi Folks,

I understand Ansys solves static problem by following steps (showing just those important to my question, order is important):

1. Material is assigned to elements
2. Shape functions and stiffness matrices are created basing Young's modulus E
3. Calculation of displacements
4. Strains are post-calculated from shape functions
5. Stresses are calculated basing material definition

(I) In case of elastic material, elastic E jumps into step no 2.
(II) But what happens in case when bilinear sig-eps material curve is used, does plastic E jumps into step no 2 anytime?

Results for cases (I) and (II) for exact configuration apart from material, generate larger displacements for case (II). And hence the question.

 

[karachun]

I`m not an expert in FEA theory but as I know - it is an iterative process in FEA to decide what elements are yielded and now have Et assigned instead of E. There are more than one method to efficiently obtain solution with less iterations.