Bulk Viscosity. High Strain Rate


While simulating a high-speed compression in ABAQUS, I noticed that with or without *BULK VISCOSITY, the energy balance shows a non-zero ALLVD (viscous dissipation). It means it is always in effect for numerical stability (also said so in ABAQUS documentation).
Is there a similar term in CalculiX source code also? I mean how does CalculiX take care of / stabilize high-speed deformation events?


Abaqus by default adds small contact damping in Explicit even when *CONTACT DAMPING is not specified:

a small amount of viscous contact damping is used by default for softened contact and penalty contact in Abaqus/Explicit

This causes the increase in ALLVD energy. There’s no such feature in CalculiX:

Contact damping is available for implicit *DYNAMIC calculations only. For explicit *DYNAMIC calculations it has not been implemented yet.

1 Like

Thanks for your reply.