How import strain outputs (and others) in a second model with diferent material properties?

[LAFer]

Hi all,

I need to import the data (mostly plastic strain) of a previous model into a second model equal, but with a different plasticity constitutive model. Things how geometry, mesh and BC stay the same. The first model works with Drucker-Prager/Cap plasticity with hardening, and the second model works with a Drucker-Prager plasticity, also with hardening.

I've been trying to apply the initial state predefined field to import displacements and strains from the first model, but whitout success. Is it possible to do this type of import by changing the material properties? Any tips on how to do this?

Thanks.

 

[FEA way]

Check this topic:

https://www.eng-tips.com/viewthread.cfm?qid=482440

Import capability will let you achieve your goal. Check its description in the documentation.

 

[LAFer]

Thanks for the answer FEA way.

I looked at these topics you posted, but, unfortunaly, I think this doesn't work on my model.
If I understand correctly, changing the material properties with the Field variable only works to change material parameters of same constitutive model, right? (e.g. change the Young modulus of a linear elastic material between steps). But I need to change the whole constitutive model of plasticity between the steps, change Cap plasticity to Drucker-Prager.

I have tried to import the strains with the initial state predefined field in a second model, but unsuccessfully. Imported initial data looks weird


Looking in Abaqus manual "9.2.1 Transferring results between Abaqus analyses: overview" is saying:

Importing the material state
You can specify whether or not the associated material state should be imported. If you choose to import the material state, the following are imported:

stresses;

equivalent plastic strains;

back stresses for the kinematic hardening models;

user-defined state variables;

damage-related state variables for the concrete damaged plasticity model;

damage-related state-variables for traction-separation response with cohesive elements;

damage-related state variables for ductile metals;

damage-related state variables for fiber-reinforced composites;

maximum deviatoric strain energy density during deformation history for Mullins effect;

internal strains and stresses for viscoelastic material models; and

connector state variables such as plastic strains, frictional slip, and damage state.

Thus, the state is imported correctly for further analysis only for the following:

linear elasticity,

Mises plasticity (including the kinematic hardening models),

extended Drucker-Prager plasticity,

crushable foam plasticity,

Mohr-Coulomb plasticity,

critical state (clay) plasticity,

cast iron plasticity,

concrete damaged plasticity,

hyperelasticity (including Mullins effect),

hyperfoam,

viscoelasticity,

traction-separation response with damage for cohesive elements,

damage for ductile metals,

damage for fiber-reinforced composites,

connector behavior, and

materials defined in user subroutines UMAT and VUMAT.

So, Cap plasticity model is not in the list of supported models by Initial State field.
Could this be the problem with my import?

Thanks in advance.

 

[FEA way]

Under this list of supported materials, it’s stated that for other material models only stresses are imported.

You can always export the deformed mesh and use it in subsequent analysis with or without the initial stress but it may not be possible to provide initial plastic strain for the cap plasticity model.