Hello, I have a written a UMAT for a hyperfoam type material in Abaqus. To validate it I am comparing my UMAT results with that from a *HYPERFOAM material definition. I am facing a particular problem:
In this study, we presented a numerically robust procedure to evaluate 4th order tangent moduli which are vital for acheiving quadratic convergence of global Newton-Raphson scheme.
In this study, the proposed method is verified for hyperelastic models alone. However, the same can be extended to other constitutive models.
The paper can be found at
Numerically approximated Cauchy integral (NACI) for implementation of constitutive models
10.1016/j.finel.2014.05.016
I am trying to run a UMAT in Abaqus but the program aborts with the following error message:
***ERROR: System error 3 std_ElemWorkspaceManager::DeAllocate: An offset overwrite was detected for Workspace idEW_MaterialStiffness (ID = 13), offset = 16.
I have searched the yahoo Abaqus usergroup and the net and it seems like a couple of people had the same problem and posted online but there are no replies, solutions or comments.
I would highlhy appreciate any help on this.
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
I have funding for software development to provide a UMAT interface in the parallel versions of the code from Smith I.M. and Griffiths D.V. "Programming the Finite Element Method", 4th Edition, Wiley, 2004.
I would be interested to hear about any open source UMATs available for download. I'd also like to hear from anyone who might like to use their closed source UMATs in a parallel environment.
The funding has been awarded by the UK National HPC Service HECToR to encourage the greater use of HECToR for Structural Engineering.
