Approximation rubber shore 60

(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

30mm seems like a large displacement even for a shore 60 duro. Is it in tension or compression? I would start with smaller displacements.

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.

Typical values are:


in your model:


And D1=2/K0,
K0 (initial bulk modulus) =imagen … leads to typically D1 = 0.001 MPa^(-1)

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so I guess your data is not in MPa and should be changed to:


Thanks for your help. I make the changes

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I tested It 's perfect

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For the fixed constants I get this in Abaqus:

I suppose with these coefficients
(C10=65.629695, C01=16.8824232, D1=0.0000121194319309088)

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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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I tested with this coefficients 0.65629695,0.168824232,0.00121194319309088
I confirm. I have tested it
Thank you for your perfect help

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