Learning Forum

[Duncan Gibbons]

Hi all,

I am trying to run a fatigue crack growth analysis using the SMART crack growth tool in Ansys mechanical/workbench 2021 R1. It seems to be taking excessively long in comparison to the static crack growth analyses I have run previously for the same setup (same mesh, loads, constraints, analysis settings, etc.) and with the same crack (same size, parameters, locations etc.). The static crack growth was solved in under 10 minutes whereas the fatigue counterpart has been running for the past 9 hours and is currently only at 50% progress. I am running the simulation on a desktop with 8 cores/16 threads and 64GB RAM.

Mesh settings: Base = 0.5mm size quadratic adaptive tetrahedral mesh, Crack = tetrahedral mesh with 6 contours and default settings.

Analysis settings: 1 step, 1s step time, auto time stepping off, 100 substeps. The rest are program-controlled and default. Nonlinear and large deformation are both off.

1. Is this common that the fatigue SMART crack growth takes excessively longer to run than the static crack growth?
2. Are there some things I should look out for and double-check to speed up the fatigue crack growth analysis (particularly with the analysis settings)?
3. What is the ballpark run time for such analyses on fairly simple geometries and setups?
4. Are there recommended minimum settings to perform an initial analysis and get quick results to verify the setup is correct?

Thanks,

Duncan