Damping dependent on time step

schrummy14 / LIGGGHTS_Flexible_Fibers

This is a modified version of LIGGGHTS that includes granular bond formulations. The original version of LIGGGHTS produced by CFDEM can be found here: https://github.com/CFDEMproject/LIGGGHTS-PUBLIC

GNU General Public License v2.0

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Damping dependent on time step #3

Closed schrummy14 closed 4 years ago

schrummy14 commented 4 years ago

The nonlinear damping equations are time step dependent. As long as you calibrate the damping at the time step you wish to use, this shouldn't be an issue. Work is being done to determine the best way to make the damping not dependent on the time step.

schrummy14 commented 4 years ago

Update: For the normal force of the bond, the problem has been fixed. More testing is needed to determine if the tangent force and moments are also fixed. This was done my multiplying the time step with beta0 and dividing beta 2 by the time step. As far as I can tell, the linear portion of the damping was unaffected (other than by numerical damping).