# Approximation rubber shore 60
**URL:** https://calculix.discourse.group/t/approximation-rubber-shore-60/1543
**Category:** Uncategorized
**Created:** [March 16, 2023, 3:18pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543 "2023-03-16T15:18:28Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@pierre](https://calculix.discourse.group/u/pierre)
#### Post date: [March 16, 2023, 3:18pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/1 "2023-03-16T15:18:28Z")
(see attached file)
I used Calculix launcher. I modelled the geometry with gmsh (2D).
The dimensions are in mm and the thickness is 10. The material is a rubber (Shore 60). I impose a displacement of -30 mm on the top and bottom line.
I modeled the Shore 60 rubber with the Mooney Rivlin model (Plastic Data -approximation rubber)
I chose dimensions in mm and in principle stresses in MPa. I find values of the order of 500, 1000 MPa instead of a few MPa
[https://secure.digiposte.fr/p/26028d5367e043cf84f2864862633ee5](https://secure.digiposte.fr/p/26028d5367e043cf84f2864862633ee5)
---
### Author:  [@jbr](https://calculix.discourse.group/u/jbr)
#### Post date: [March 16, 2023, 9:39pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/2 "2023-03-16T21:39:51Z")
30mm seems like a large displacement even for a shore 60 duro. Is it in tension or compression? I would start with smaller displacements.
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### Author:  [@Calc\_em](https://calculix.discourse.group/u/Calc_em)
#### Post date: [March 16, 2023, 10:50pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/3 "2023-03-16T22:50:14Z")
Here’s what the uniaxial stress-strain curve for the Mooney-Rivlin model with these constants (C10=65.629695, C01=16.8824232, D1=0.0000121194319309088) and range of strains shown in your analysis (-0.23 to 4.3) looks like:
It’s from Abaqus.
Btw. how did you obtain those coefficients ?
The mesh in your model is strange. It’s very fine away from the hole and very coarse around the hole. It should be the opposite.
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### Author:  [@JuanP74](https://calculix.discourse.group/u/JuanP74)
#### Post date: [March 17, 2023, 9:43pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/4 "2023-03-17T21:43:57Z")
Typical values are:
[https://www.researchgate.net/publication/323203919\_Rubber\_bushing\_hyperelastic\_behavior\_based\_on\_shore\_hardness\_and\_uniaxial\_extension](https://www.researchgate.net/publication/323203919_Rubber_bushing_hyperelastic_behavior_based_on_shore_hardness_and_uniaxial_extension)
in your model:
```auto
*MATERIAL,NAME=s60
*HYPERELASTIC,MOONEY-RIVLIN,
65.629695,16.8824232,0.0000121194319309088
```
And D1=2/K0,
K0 (initial bulk modulus) =  … leads to typically D1 = 0.001 MPa^(-1)
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### Author:  [@JuanP74](https://calculix.discourse.group/u/JuanP74)
#### Post date: [March 17, 2023, 9:46pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/5 "2023-03-17T21:46:15Z")
so I guess your data is not in MPa and should be changed to:
```auto
*MATERIAL,NAME=s60
*HYPERELASTIC,MOONEY-RIVLIN,
0.65629695,0.168824232,0.00121194319309088
```
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### Author:  [@pierre](https://calculix.discourse.group/u/pierre)
#### Post date: [March 18, 2023, 9:47am UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/6 "2023-03-18T09:47:53Z")
Thanks for your help. I make the changes
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### Author:  [@pierre](https://calculix.discourse.group/u/pierre)
#### Post date: [March 18, 2023, 11:44am UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/7 "2023-03-18T11:44:09Z")
I tested It 's perfect
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### Author:  [@Calc\_em](https://calculix.discourse.group/u/Calc_em)
#### Post date: [March 19, 2023, 5:39pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/8 "2023-03-19T17:39:42Z")
For the fixed constants I get this in Abaqus:
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### Author:  [@pierre](https://calculix.discourse.group/u/pierre)
#### Post date: [March 20, 2023, 12:20pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/9 "2023-03-20T12:20:55Z")
I suppose with these coefficients
(C10=65.629695, C01=16.8824232, D1=0.0000121194319309088)
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### Author:  [@Calc\_em](https://calculix.discourse.group/u/Calc_em)
#### Post date: [March 20, 2023, 12:39pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/10 "2023-03-20T12:39:14Z")
No, it’s for the new ones (0.65629695,0.168824232,0.00121194319309088). The previous plot was for the original coefficients: 65.629695,16.8824232,0.0000121194319309088.
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### Author:  [@pierre](https://calculix.discourse.group/u/pierre)
#### Post date: [March 20, 2023, 4:58pm UTC](https://calculix.discourse.group/t/approximation-rubber-shore-60/1543/11 "2023-03-20T16:58:26Z")
I tested with this coefficients 0.65629695,0.168824232,0.00121194319309088
I confirm. I have tested it
Thank you for your perfect help