Speeding up Simulations for Focused Studies

In several situations, simulation models (new or inherited), are quite often burderend with several expensive features that may have negligible effect on the response that is purely used for comparative numerical studies. When a large portion of any simulation model turnaround time consists of features that are irrelavant to the focued study, it is imperative that such features must be turned off to improve the overall turnaround time. Alternative methods could include the usage of a faster and increased number of processors which involves additional cost and availibility. However, a more effective solution would to simply review the model and look for expensive features that has little no bearing on the objective of the study and suppress them. A list of features that was encountered recently while studing the effects of the parameter DPRFAC, the results of which will be published soon, was the following:

1. Switch to One-Point Integration Shell Element (Type 2 Shell) and use appropriate hourglass control
2. Use of fast rigid body treatment since no rigidbody rotations was involved
3. Reference a box to limit number of contact segments
4. Coarsening of regions of mesh outside of the study
5. Increased rate of loading
6. Turn off membrane thinning effects for both element and contact calculations
7. Increased mass scaled timestep

The changes above were parameterized using *PARAMETER_EXPRESSION to facilitate a seamless restoration of the original features in just one place in the input file with minimum effort and time. With the above changes, the turnaround time was roughly 6 minutes, from an original turnaround time of 1 hour, which was invaluable as it gave me continuity in the postprocessing. A total of over 20 simulations were run to study the effects of DPRFAC, and with a saving of an hour per simulation, it worked to be around 20 hours.

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