Linear and Quadratic Bulk Viscosity parameters in Explicit dynamic analysis

[Ravi K Mudragada]

While performing "Blast analysis on a RC frame (single bay single story)" analysis resulted into mesh distortion due to high velocity gradient.
Abaqus manual says; introducing the numerical damping into the system will damp out the volumetric straining and avoid mesh distortion due to high velocity gradients. Therefore, I have tried with default values of linear and quadratic bulk viscosity but still problems persisting. Abaqus says; we can't choose these values randomly because high values of bulk viscosity would result into mesh locking and effect the results. So, my question is
What is the limit values for linear and quadratic bulk viscosity parameters in Explicit Dynamic analysis ..?
Default values says: Linear = 0.06 and quadratic = 1.2

 

[FEA way]

There’s no such limit. In this case you should try different values and carefully check the results to make sure that they are correct and not too much affected by the numerical damping.