Hello

you can find the implementation of a Maxwell model in parallel to a spring in my PhD thesis:

Upsetting and Viscoelasticity of Vitreous SiO2: Experiments, Interpretation and Simulation

PhD Thesis, Technische Universitaet Berlin, Germany, 2006

https://depositonce.tu-berlin.de/handle/11303/1574

I have posted the analogous procedure for the Kelvin-Voigt model on

http://imechanica.org/node/12702

Good luck

Frank

 Thanks Frank.

I used your PhD thesis and it was very useful for me. 

You did a good job.

So why then did you post that question ?

Dear Frank

First, I used your code and I model the viscoelastic material and run the Abaqus code for general, static model; however, there are large deformations and distortion of elements and Abaqus is aborted. I changed the problem from standard to explicit and use adoptive remeshing. However, I should use VUMAT for the case of Abaqus/Explicit. I want to write a VUMAT for a 3d model of standard linear solid model. you wrote a UMAT; however; I don't know how to use it for explicit one.

Thanks

Dear Jamaleddin,

please accept my apology, the "V" escaped me.

There is ostensibly a fix to use a UMAT as VUMAT:

http://www.soilmodels.info/node18.html

You can also try to get assistance from the

ABAQUS mailing list

https://groups.yahoo.com/group/ABAQUS

Search the archive before posting.

For an intro to subroutines get the file

http://imechanica.org/files/Writing User Subroutines with ABAQUS.pdf

I have no access to ABAQUS at present.

Let us know your progress.

Good luck

Frank