Rolling and Torsion interactions

Friction contact forces in MercuryDPM implemented as FrictionSpecies, FrictionInteraction

Header:

#include <Species/FrictionForceSpecies/FrictionSpecies.h> 

Interaction function:

#include <Interaction/FrictionForceInteraction/FrictionInteraction.h> 

It contains, rolling friction and torsion friction.

The user can use one of the following species into the main program:

include <Species/LinearViscoelasticFrictionSpecies.h>

include <Species/LinearPlasticViscoelasticFrictionSpecies.h>

include <Species/HertzianViscoelasticFrictionSpecies.h>

include <Species/HertzianSinterFrictionSpecies.h>

Self Tests:

TorsionFrictionSelfTest.cpp

RollingFrictionSelfTest.cpp

Torsion force model