# Thread: Hyperelasticity parameters

1. Junior Member
Join Date
2009-06
Posts
29

## Hyperelasticity parameters

I am working on Abaqus example 3.1.8 Tread wear simulation using adaptive meshing in Abaqus/Standard.
The following characteristics are given for rubber material :
*Material, name=RUBBER
*Density
1100.,
*Hyperelastic, moduli=LONG TERM
1e+06,0.,2e-8
I haven t found, on the abaqus guide, which parameters are related to the numbers 1e+06,0.,2e-8.

2. That sounds strange. Typically you need to specify which hyperelastic model to use (and not only *Hyperelastic). Perhaps one of the models is the "default".

I recommend that you add the the specification of what hyperelastic model you would like to use.

-Jorgen

3. Junior Member
Join Date
2009-06
Posts
29

## rubber material parameters

I am running a cylindrical rubber on a rigid surface. I have searched on the Abaqus and general bibliography and I have understood the different models that can be used but I haven t found good data to fill in.
So I have used data from an abaqus code on a similar problem but I didn t understand the meaning of the number I filled in...someone knows more suitable rubber material characterization for ABAQUS modelling purpose?
#
THANKS

4. I recommend that you read the section in the Abaqus user's manual that discusses the *Hyperelastic command.

-Jorgen

5. Junior Member
Join Date
2009-06
Posts
29
I know that section by heart...My question was about reasonable value to put inside the program.

I am working with the following parameter (from literature) but I have quite large deformations.
C10 c01 D1
1 0.8 0.0122
Probably they refer to a different kind of rubber (I am studying tyre rubber).

6. Since your C10 and C01 values are both positive your model will be stable, the C10 value is rather small which corresponds to a soft rubber. Since I don't know what material you are studying I cannot provide detailed feedback on material parameters

-Jorgen

7. Junior Member
Join Date
2008-12
Posts
5

## viscous parameter

I want to know witch parameter represent the amount of viscosity in the model of hysteresis.
because i have two phases in my model,and i want to make an important contrast between two phases by increasing or decreasing the viscousity.
in the hysteresis model in abaqus,there are this parameter:
1)Stress Scaling Factor
2)Creep Parameter
3)Eff Stress Exponent
4)Creep Strain Exponent
so witch parameter enable as to modify viscousity? It will be useful for me to explain also others one
in abaqus they are defined in this way.
1.

Stress scaling factor, S.
2.

Creep parameter, A.
3.

Effective stress exponent, m.
4.

Creep strain exponent, .
5.

Constant, , for regularizing the creep strain rate near the undeformed state. The value of should be non-negative. If this field is left blank, the default value of 0.01 is used.
there is also relation between some parameters such as A and m
also some typical value (S=1.6 etc...),please I need to understand the signification of each parameter,and witch parameter represent the effect of viscosity.

8. I recommend that you check out a new web-site that I am working on :
http://polymermechanics.com/material...ergstrom_boyce

What is nice about this website is that you can try out different value and see how they influence the predicted stress-strain response.

Note that I use a slightly different nomenclature than Abaqus:

Abaqus "s" : same as my "s"
Abaqus "m": same as my "m"
Abaqus "C": same as my "C"
Abaqus "A": is given by 1.0 / (tauBas)^m

In short, the viscosity is mainly controlled by: S, A, m

9. Junior Member
Join Date
2008-12
Posts
5
many thanks Jorgen for your help.

10. Junior Member
Join Date
2009-11
Posts
6

## Hi

Iam currently running an analysis of a piping system in ABAQUS, Iam modelling using shell elements and shell parts.Iam really struggling with the hyperelastic parameters .

What is D

and C01 ,C11.

I would apprecciate if any one can recommend some rubbber like parameters for application.

Many thanks

Mohamed El-Abiary

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