yade-dev team mailing list archive

["Sergei D." <sj2001@xxxxxxxxx>]

> Yes, en and es are normal and tangential coefficients of restitution
> (ratio of velocities after and before the 'impact': vf/vi).
> I wanted to say that the parameters in
> SimpleViscoelasticBodyParameters could be the stiffnesses and
> restitution coefficients. Then, the effective mass together with the
> viscous constants could be determined in
> SimpleViscoelasticRelationships (maybe with the equations you showed me).
I do not quite understand the idea. At this point, 
SimpleViscoelasticBodyParameters contains the viscoelastic parameters of
a single body, i.e. its stiffnesses and viscosity.
SimpleViscoelasticRelationships  defines the effective  parameters of
interaction between two different viscoelastic bodies (by analogy with
the effective Young's modulus).

The idea of this. The viscoelastic parameters of a single body can be
defined in various ways including using collision time and restitution
coefficient (which are functions of mass, radius and material of
collising bodies) for the collision of a pair identical bodies. Then,
using the parameters for the bodies from different species, it is
possible to calculate the effective parameters of their interaction.