UMAT - insufficient memory

[StevenJS]

Hi all,

I created a UMAT, that is used for lineair softening of a material in tension and shear (2D).
For small models this UMAT works just fine, and correct results are obtained.

However when using the UMAT in a larger model (+- 1500 UMAT elements, 1500 standard Abaqus material elements).
i get the following error message:

---------------------------------------------------------------------------------
***ERROR: Abaqus/Standard has exited because there is insufficient memory

***ERROR: Abaqus/Standard has exited because there is insufficient memory
available. A limit of 90 percent of physical memory was specified
available. A limit of 90 percent of physical memory was specified
using the memory parameter. The physical memory available on the
using the memory parameter. The physical memory available on the

***ERROR: Abaqus/Standard has exited because there is insufficient memory
machine in use is 8079.23 megabytes. The user may need to run this
machine in use is 8079.23 megabytes. The user may need to run this
available. A limit of 90 percent of physical memory was specified
analysis on a machine with more physical memory.
analysis on a machine with more physical memory.
using the memory parameter. The physical memory available on the
machine in use is 8079.23 megabytes. The user may need to run this
analysis on a machine with more physical memory.

***ERROR: Abaqus/Standard has exited because there is insufficient memory
available. A limit of 90 percent of physical memory was specified
using the memory parameter. The physical memory available on the
machine in use is 8079.23 megabytes. The user may need to run this
analysis on a machine with more physical memory.
---------------------------------------------------------------------------------


Thus indicating my RAM memory is to small to complete this simulation.
However this simulation is not that big, and runs just fine when using comparable Abaqus material models,
The problem has to be in the UMAT or communication between Abaqus and the UMAT.

Is there any way to find out what in the UMAT causes such a large request for the memory.
And does anyone have any suggestions on how to reduce the required memory size for simulation with a UMAT?


Thanks in advance for any help!

 

[burningDiesel]

Maybe you are allocating a matrix (possibly with mostly zeros) of a higher size?
Using double precision you get to 8GB quite fast (espec with dimensions > 2). e.g. DIMENSION MAT(100,100,100,100) would be 1 GB.
That would be my first guess.