large deformation in hyperelastic model: no convergence

[herminator]

Hi,

I already posted a part of my problem some weeks ago. Since the first issues are solved, I have a problem with large strains in my model.
I simulate two hyperelastic layers that lay one on the top of the other. The two layers are made out of two different materials, both hyperelastic. I use mooney rivlin with two parameters.
On the bottom of the layers there are several rigid bodies that move into the layers. From above a surface load on the upper layer is pushing. Figuratively the two layers are pinched due to the rigid bodies and the the surface load.

The rigid bodies move in 30 steps a total distace of 3mm. The layers are fixed on the edges. For a total distance of 3mm the simulation works. When I change this distance to 4mm, the simulation does not converge anymore, even with 50 load steps.
Do you have any suggestions what to change? ("large deformations" is on)

convergence.jpg
The attached picture shows the force convergence of my simulation. Everything looks fine until a certain load is exceeded.

I use Ansys Workbench 13

Thanks in advance!

[Ashutosh.srivastava]

Hi,

I already posted a part of my problem some weeks ago. Since the first issues are solved, I have a problem with large strains in my model.
I simulate two hyperelastic layers that lay one on the top of the other. The two layers are made out of two different materials, both hyperelastic. I use mooney rivlin with two parameters.
On the bottom of the layers there are several rigid bodies that move into the layers. From above a surface load on the upper layer is pushing. Figuratively the two layers are pinched due to the rigid bodies and the the surface load.

The rigid bodies move in 30 steps a total distace of 3mm. The layers are fixed on the edges. For a total distance of 3mm the simulation works. When I change this distance to 4mm, the simulation does not converge anymore, even with 50 load steps.
Do you have any suggestions what to change? ("large deformations" is on)

convergence.jpg
The attached picture shows the force convergence of my simulation. Everything looks fine until a certain load is exceeded.

I use Ansys Workbench 13

Thanks in advance!

Did you see where the newton rapson residuals are showing up? I also see that the force convergence is going below reference but still solution is uncovereged. This might be due to the volumetric convergence issue. Try using Keyopt(6)=1 for the elements with hyperelastic properties.

Regards,

Ashutosh