Non Smooth Laws¶
A non-smooth law is an object used to define the behavior of the systems involved in an Interaction, when a non-smooth event occurs. For example, in the case of an impact, a Newton impact law will link the pre and post velocities at impact in something like “post-velocity = -e X pre-velocity”.
Each non-smooth law is characterized by:
a type (more or less the name of its class), i.e. what kind of law is required
the size of vectors involved in the law
some specific variables depending on its type.
Nonsmooth laws are defined in classes which name ends with “NSL”. All of them are derived from an abstract class which defines a generic interface, NonSmoothLaw.
Available classes: NonSmoothLaw, ComplementarityConditionNSL, EqualityConditionNSL, MixedComplementarityConditionNSL, MultipleImpactNSL, NewtonImpactNSL, NewtonImpactFrictionNSL, RelayNSL, NormalConeNSL.
nsLawSize: 1. no specific parameters.
parameter: e, the Newton normal coefficient of restitution.
nsLawSize: 2 or 3 (2 or 3 dimensional friction).
parameters: en, et (Newton impact normal and tangential coefficients) and mu, friction coefficient.
Newton Impact Law plus Coulomb Friction.
In this case, y components are in the following order:
first relation, normal part
first relation, tangential part
relation n, normal part
relation n, tangential part
and so on .
Note also that usually only normal part definition is required for y.
parameters: c and d