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VUMAT viscoelasticity (Maxwell model)

Submitted by surot on
research
viscoelasticity
VUMAT
ABAQUS

Dear all,

I would like to ask you for advice. I am about to simulate a pull-through test (see attached picture) of a cladding panel made of a material with highly viscoelastic behaviour. I have parameters for Maxwell model (Prony series) obtained from test. I expect large deformation and probably cone failure (or tearing of the cladding panel). Therefore I would like to use Abaqus/Explicit. The problem is that I cannot use *visco step together with Explicit. Is there any way to solve it?

Question reg ABAQUS-VUMAT and Updated Lagrangian formulation.

Submitted by ksrikanth523 on
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Computational Mechanics Forum
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viscoelasticity
Abaqus VUMAT
VUMAT
ABAQUS

Hello all,

I am working on implementing a viscoelastic constitutive model from a hyperelastic stored energy potential (for finite-elasticity) and a dissipation potential (for the viscouls evolution). The elastic constitutive relation, hence derived from the stored energy potential is rate-independent and it is expressed as T(Cauchy's Stress) = f(B), where B is the Left-cauchy green deformation tensor.

The evolution equation is derived out in an objective rate form, which I am integrating over time using a 2nd order accurate explicit method.

My question:

Polycrystal plasticity in Abaqus/Explicit

Submitted by Karol Frydrych on
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Computational Mechanics Forum
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VUMAT
Abaqus/Explicit
Plasticity
adaptive meshing
Crystal plasticity

Hello everyone!

My goal is to model large plastic deformations of polycrystalline metals using crystal plasticity and ALE adaptive meshing. In order to do that I want to use VUMAT subroutine in Abaqus/Explicit, since as far as I understand Abaqus/Standard is not good for large deformations and it doesn't support ALE adaptive meshing for that purpose.

New publication for UMAT and VUMAT in ABAQUS

Submitted by safaei on
UMAT
VUMAT
ABAQUS
flow rule
Explicit
Abaqus implicit

We performed a comprehensive study of a large class of Implicit and Explicit integration algorithms for Elastic-Plastic behaviors in Finite Element Analysis (FEA) developed in UMAT and VUMAT for ABAQUS and presented various unique results. We also showed detailed integration algorithms for both Associated and Non-Associated Flow Rules with mixed isotropic and kimenatic hardening with expandable number of internal variables (damage and etc).

Full bibliographic details:

VUMAT general queries

Submitted by shindemh07 on
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ABAQUS
VUMAT
VIB

Hi,

I am beginner in abaqus and I want to write a VUMAT for VIB method to simulate fracture, while writing VUMAT i encountered following problems 

1) For 2D plane stress problem how to calculate strainInc(*,3). It is increment for that step or value of strain till that step?

2) What is effect of that defination on answer I am getting?

VUMAT of Drucker Prager, help needed please..

Submitted by Gayan Aravinda on
education
VUMAT
VUMAT abaqus Drucker prager

Hi Everyone,

                    I have written Drucker Prager in VUMAT version as shown below..but still there are some deviation with the original in built version of ABAQUS. I have all the notes how i derived these equation.could you please show me where the code has gone wrong or have i missed a critical point in here..i tried my best to spot the error but could not..may be you all experts could find it. Thank you very much. 

 

subroutine vumat(

c Read only -

vumat for isotropic perfect plastic

Submitted by Gayan Aravinda on
VUMAT

Hi all,

        I wrote VUMAT subroutine using fortran 77 for perfect plasticity unisng von mises plasticity..when analysed it using unidirectional tensile simulation for a simple cube model...it seems to me that it only goes through elastic deformation and not plastic...i tried to find out what is the error..but could not find it..could anyone please find what is the error in this code..i have attached the VUMAT code for the reference...thank you very much...

 

subroutine vumat(

Use Vumat to simulate the hot ductile fracture criterion of Freudenthal

Submitted by hongfengtl on
research
fracture
VUMAT
Freudenthal

Dear everybody，

I have just studied Abaqus and would like to use Vumat to simulate the hot ductile

fracture criterion of Freudenthal which have the equation: D=integral(0-fracture strain)

of (Smises stress)*d(strain). The fracture will be appear when I reach 1 unit.

Could you please show me how to write algorithm adding temperature to calculate (D) and

out put (D) in Vumat.

thanks you so much

I am looking forward to hearing from you

hongfengtl    

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