Applying residual stress without using node numbers - Implicit and Explicit analysis

[structuraleng10]

Hi folks,

I'm trying to apply residual stress pattern (with discrete values) in a cold-formed section (E.g. C-section) in a automatic manner (Python code function of the geometry).

Which command in Python I can use to associate initial stress to the lines (instead of nodes)? This is because I would like to do some parametric studies by changing the length of the section or even the number of elements but keeping the value of the residual stress, for example in the web, constant.

E.g. C-section:

flange
--------¦
|.A ¦
web |.B
|.C
|.D
--------¦
To explain with a drawing, I would like to have different residual stresses in A-B and B-C but constant along each of them. And I want to change the number of elements along A-B from one analyse to another.

My aim is to do it in explicit analysis but it would help me if I learn to do it in Implicit analysis too.

 

[Mustaine3]

Maybe you should check out first on what kind of entities you can apply initial stresses. After that you can think about a way to do that.

 

[kkbabak]

use "*initial condition" command to add residual stress as initial stresses!
put this command between BCs and step in your .inp file.

the format of this command:
*initial condition,Type=stress,
setname,a,b,c,d,e,f

a~f are principle stresses and setname is the predefined set to assign residual stress.

 

[structuraleng10]

Thanks Mustaine!
This is my problem.
I think that with the traditional command (*initial condition) I can only apply at nodes. I found that I can use a subroutine to apply at integration points too. Do you know more entities that I can apply it?

Thanks kkbabak!
Exactly this I was trying to do but the problem for parametric studies it that this "setname" should be a set of elements, as far as I know. If I change the number of element, I need to create a new set. This process make unfeasible any parametric studies.

 

[Mustaine3]

I think that with the traditional command (*initial condition) I can only apply at nodes.

You should really have a look into the manual.