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Abaqus CAE with dynamic explicit/implict

msd.jacob's picture

I want to get the stress value in the roller of a hot/cold worked plate. Both the roller and the plate are defrormable 2D shell model. The change in the thickness of the plate is 0.05mm once the plate  passes throguh the rolees.I am trying to use dynamic explicitt in the step process. PLease advice me wat are the other factors i have to input for the dynamic explicit process. I am having some more input for the roller and the plate velocity.

Please advice me or just ask me for further input. Thanks for your mehaniciams feed back.



There is an active Yahoo group at where Abaqus related issues are discussed.  You could try to get your answers from the members of that group before falling back on iMechanica.

msd.jacob's picture

Thanks Banerjee for your input

msd.jacob's picture

Hi groups,

can any one suggest where to get a simple UMAT subroutine program written in fortran to understand the basic of subroutine in abaqus. I checked with abaqus.doc, but there is no simple program with explanation for a starter. Please guide.Thanks in advance

rkannabattula's picture


    You can find few example problems with an input file along with UMAT subroutine in Abaqus documentation. The examples can be found in Abaqus verification manual (in User Subroutines section). They only mention the file names. you can fetch those files from the follwoing command

abaqus fetch job=<name of the file>

For example in abaqus 6.6, I found the following input file with UMAT subroutine for 2D hyper eleasticity mentioned in verfication manual.



I'm sorry if you already know this information. 


Ratna Kumar 

Arun Prakash's picture



What do you intend to program? If you
require "starter" routines like linear elasticity or von-Mises
Plasticity you will find them in the ABAQUS documentation. (just as
Ratna has suggested) Just search on UMAT for linear elasticity for
instance. You can use the structure of these routines to program more
complicated ones. Most routines are under User subroutine reference
manual or verification manual



msd.jacob's picture

Thank you guys for your input.


i want to know the how to write UMAT subroutine for progressive failure of composite material. in ABAQUS. or from where i can get any similar kind of subroutine so that i can understand the basic of subrouitine. please help me

I suggest that you follow the suggestions in this thread and write simple UMAT first before going to deal with progressive damage. Coding progressive failure
in FEM needs numerical techniques like damping in your constitutive model such that the stiffness matrix has positive det. There should be tens of publications on this topic. Another option is to use VUMAT in Abaqus. 


thanx for advice Yujie but if i get the example UMAT for composite failure then i can model it because of the time limit. so please suggest me any source to get that or similar typ of example UMAT subroutine.

i want to run the following job using abaqus,but i face alot problem.
would you please help me and take look it an corre

Hi Everyone,

I am doing a project in which I am trying to study about the drilling of composite. The aim is to optimize the drill and process parameters to minimize the damage. For this I have tried to simulate the drilling process in ABAQUS and I am using the Hashin damage model. The problem is that Hashin damage model works only for the lamina which takes only plane stress elements. Since only plane elements are allowed I am unable to simulate cutting action of drill as the composite plate is effectively 2D.

When I take 3D elements then Abaqus shows error that Hashin damage model cannot be applied for that plate. Also there is no other damage model for composites in Abaqus.

As a result, I am stuck in this project. Please suggest.



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