I want to understand how the stress update algorithm is modified for the different definitions of stress rate in ABAQUS/Standard and ABAQUS/Explicit formulations. I know the relationships, I just want to see how it's coded in a subroutine.
Also, the Hughes-Winget algorithm is used to update the stress defined by the Green-Naghdi stress rate by using the Jaumann rate. How to implement that in VUMAT? Can someone please post an example to clarify these aspects?
I wonder if there is any subroutine interface to have access to nodal ( not integral point ) displacement in abaqus DURING the analysis phase. Suppose I have a field that is going to be used in UMAT and that is dependent on displacements of all nodes (presumably stored in an array) from the last increment. Is this possible to be implemented within Abaqus?
I found that there is no comprehensive topic about how to calculate material jacobian matrix for UMAT while it's one of the most complicated and important parts of writing a subroutine and a lot of the researchers deal with it.
I think it would be great if experts share their sources and experiences here for all. I personally, try to provide the basics and essential materials as well.
I have now managed to run the fortran code, but it won't assign the values that I want to assign to the U(1) variable from the TXT file.
In the attached file I have the Fortran file that I am working on, the input file Subroutine1 (save it as .inp file to open in Abaqus) and the pressure file that contains the nodes and the corresponding pressure values which I want to assign through DISP Subroutine. The code below
I am a student studying in Hamburg University of Technology. I am currently doing my thesis and want some help in finishing it. I am finding it a bit difficult to do subroutine in Fortran as I am new to it. I have tried learning from Abaqus Documentation but I didn't get answer to my needs.
Im trying to implement subroutine umat and run a job.but im getting this error through abaqus cae and cmd (attached file),was wondering if anyone could help me out?im using abaqus 6.10 -VS2008-IVF 11 AND successfully run some examples from abaqus verification.i also can send my fortran file ( .for) and input abaqus file for more clarification if you require. any help really apreciated.
I am playing a bit with subroutines in Abaqus 6.13 to understand how they work. At the moment I am using a VUSDFLD to variate the stiffness/density/conductivity in a model (I defined the field variable) depending on Temperature and Position.
It seems that there are not particular errors in the inp file and in the for file, but I got this error in the .sta file:
***ERROR: Internal error in look-up table generation. Check that dataline entries are sufficient to describe the dependence in all independent variables.
I am working on vufiled subroutine for abaqus. I already have a named common block statement in my vfriction subroutine. I need the values from the common block be read in vufield subroutine and passed further / saved to a field variable to be able to plot a contour plot.
Can anyone share his ideas about the coding or have an advice for me?
Recent comments