Learning Forum

[SallyUIdaho]

Hello Everyone,

I am trying to model the behavior of a biological material in a fluid-structure interaction (FSI) simulation. I am using Fluent and Transient Structural for the coupling. The biological material is modeled as a hyperelastic Ogden material up to the failure point (failure point is the maximum stress). I was a able to successfully run the FSI simulation with the Ogden constants. Now I am trying to add damage modeling to the biological material as well. I know it is possible to combine linear elastic with damage. However, I am having problems with using a hyperelastic model with damage. I get an error that says "More than one material option has been defined for material 1. Hyperelastic material (TB,HYPER) is not supported with other nonlinear material models." I haven't had any luck looking online; is it possible to combination hyperelastic modeling with damage in ANSYS?

Thank you for your time and help.

[jj77]

This is very complex what you are doing.

 

I have never seen a damage model for hyper-elasticity, and a quick search on the internet did not give much (no mention in ansys and abaqus manuals).

 

There are different general failure criteria as say the max principal (tensile) stress for ductile material. Perhaps you can use that and see where it fails, or get the largest strain, and compare that to the elongation/strain at break for the material.

 

Hope someone else has some more feedback.

[juan.rojas]

Are you trying to use mullins effect? I haven't worked in something similar to you, but I would check the material if there are any unnecessary properties, or even define it from scratch adding the things you need only. I would also think that maybe it can't do something that complex and it's telling you to remove any other non linear effect. If with only hyperelastic and damage model, I would try a simpler hyperelastic model (neo hookean for instance) and check if it's still giving you issues.