VISCOPLASTIC LAW - Norton Hoff - ABAQUS ?

[Lemine]

Hello Engineer's,

I'm having trouble to set the dissipation potentiel of Norton Hoff below (cf.Image) to model the viscoplastic reponse of structure in Abaqus.
I want to know if programming UMAT It is the only way to overcome this problem?

Thanks in advence for your help
Regards,

 

[Mustaine3]

Have you checked the documentation? See at help.3ds.com
Reference Library > Abaqus > Materials > Inelastic Mechanical Properties > Metal plasticity > Two-layer viscoplasticity

But if the implemented method is not sufficient for you, then there is no other option than a UMAT to implement your own theory.

 

[Lemine]

Thanks a lot dear Mustaine for your reply.
Is it possible to determine the parameters of two-layer viscoplasticity model in Abaqus (A,n,m,f) from the expression of dissipation potential ?
If the umat is the only solution I would be so thankfull if you can share a Umat exemple near to my case.

Thanks a lot,

 

[FEA way]

There's also a CREEP subroutine that can be used for used-defined creep laws but if its capabilities are not sufficient for your goals then you need full UMAT.