bilinear constitutive law

[linab]

hello

Does anyone know how to define a bilinear constitutive low in Abaqus?

 

[gurmeet2003]

linab,
It is very simple. First thing is to convert from engineering stress and strain to true stress and strain. Following formulas will help:
Stu=Su(1+e)
et=ln(1+e)
I think the symbols are self explanatory. ABAQUS asks for two points to define the bilinear curve. Of course one point (0,0) is already known. Therefore add the following points:
0, Sy
et, Stu.

Gurmeet

 

[linab]

10x for ur answer,

but i didnt find a material that can define it.i can only approach it by an hyperelastic material. How can we enter the curve except by a subroutine?

Lina

 

[gurmeet2003]

Pick plasticity. It will allow you to enter true stress and true strain in a tabular fashion.

Gurmeet