Abaqus Explicit Element Dissapear

[sergiR]

Hi,

I'm running an impact simulation for a composite laminate. I'm using 2 VUMAT subroutines. I submit the input file in a cluster of my university. Apparently randomly, when I use parallel processing, some elements of the model disaper suddently from an increment to the subsequent. Simulation is terminated due to Excessive Distortion of those elements.

I've found that this never happens when I use not many CPU's (4-6). When I use more CPUS (8,12,...) this error apears, but not always....

I attach an image of the elements deleted without any reasonable explanation.



Any help would be appreciated.

 

[IceBreakerSours]

Are you using 'double precision' in both simulations?

*********************************************************
Are you new to this forum? If so, please read these FAQs:

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083

 

[sergiR]

Thanks IceBreakerSours for the response.

I am always using single precision since double precision extremelly increases the computational time and same results are obtained (with preliminary simple models).
You think this could be the source of the problem?
I have initially considered it but, if I am right, it should be not afected by the number of CPU's used to parallel processing, since double precision only concerns to the internal variables of VUMAT subroutines, which are computed at each CPU indepentlly the number of domains used for parallel processing.

I would try to run the model in double precision and different CPU parallelizations.

Thanks again for the advice.

 

[IceBreakerSours]

Single precision is a BAD idea; it is used more for something that is not terribly "consequential" from an engineering perspective. While you are varying the # of CPUs, check if the job is running on ONE node or multiple nodes. If you do not know how, you might have to talk to one of the cluster admins.

*********************************************************
Are you new to this forum? If so, please read these FAQs:

http://www.eng-tips.com/faqs.cfm?fid=376

http://www.eng-tips.com/faqs.cfm?fid=1083