Nonlinear Material with MATX42

Altair Forum User

Hello dear Altair Forum,

 

I want to calculate non-linear material in OptiStruct solver.

 

But I have the problem that the solver is calculating farther linear material with material card MAT1. The solver should calculate by MATX42 through the given ALFAi and MUi.

 

I think the material is still calculated according to MAT1 by using the given  Young's Modul.

 

It is not possible to remove the Young's Modul, because of the following error:

 *** ERROR # 1525 ***
 for material id = 1 referenced from property id = 1.
 E is set to zero for MAT1, producing singular (identically zero)
 membrane and bending matrix.

 

Here is the fem file:

 

I wish you a nice day and looking forward to your help.

 

Best regards

 

S. Gholami

 

 

Unable to find an attachment - read this blog

Altair Forum User

Hi @Sahar

 

What is the objective of the analysis?

 

Since you are using non linear hyperelastic material, did you check MATHE in OptiStruct?

 

 

Altair Forum User

Thank you for your quick answer.

the objective of this analysis is to specify a material.I received  data from an experimental single-axis compression test. I didnt check MATHE in Optistruct yet but I've got an hyperelastic material and am supposed to analyse the geometry with matx42.

 

Thanks a lot for your support.

s.gholami

Altair Forum User

Hi @Sahar

 

Since you are using linear static analysis type MATX42 will be ignored for this analysis type and MAT1 parameters will be considered.

 

MATX42 is only supported for Nonlinear geometric with EXPDYN analysis type. 

 

You can also use RADIOSS directly to use the same material. There it is called MAT/LAW42