Transferring results from Explicit to Standard with hyperelasticity

[simulation_engineer_2022]

Hi everyone!

I'm trying to calculate natural frequencies of assembly containing hyperelastic parts under load.

Due to complex contact conditions and high deformations Abaqus/Standard tends to diverge analysis and I've calculated stress state of this structure in Abaqus/Explicit. I know that Abaqus has feature to import Explicit results to Standard solver, so the idea was to simulate loading in Explicit, then import this results to Standard, conduct static step and then calculate natural frequencies.

I've double checked documentation and there is a mention that hyperelastic results can be transferred between Explicit and Standard, but the problem is in elements type. In Abaqus/Explicit there is no hybrid hexahedral elements, but Abaqus/Standard requires hybrid element type.
I've found *DIAGNOSTICS, NONHYBRID INCOMPRESSIBLE=WARNING option which supposes to turn error of using non-hybrid elements to warning, but it seems not helpful, analysis preprocessor still displays an error. I also guess this is not recommended option.

INCOMPRESSIBLE HYPERELASTIC MATERIALS CAN ONLY BE USED WITH HYBRID, PLANE STRESS, OR 1D ELEMENTS. AN INCOMPRESSIBLE MATERIAL NAMED material_name IS USED WITH A NONHYBRID ELEMENT 1 INSTANCE instance_name.

Due to prescribed condition of initial stress state I'm also unable to change the element type in Standard analysis.

I've tried using tetrahedral hybrid elements in Explicit solver, but it turned out that this C3D4H element type is not available for results transferring.

I'm also unable to correct material model constants because it is defined as a test data, but I also guess it is not good option either.

Do any users have ideas how to resolve this issue?

Much obliged in advance.

 

[FEA way]

Maybe Abaqus/Standard will also be able to solve this problem involving complex contact conditions and large deformations with some tweaks in settings. Dynamic implicit step type often turns out to be sufficient.

The *Diagnostics, nonhybrid incompressible=warning keyword should work properly for nearly incompressible materials (with an effective PR > 0.495) but won't work for fully incompressible materials.

 

[simulation_engineer_2022]

FEA way, thank a lot!

Seems that Implicit dynamic solver is the option that fits well in this case. At least job is on half-way to finish for now.