Abstract
We investigate two lumped parameter friction models: A dry-friction model (in 2-D) and a Coulomb friction model (in 8-D). The aim is a dynamical simulation of the relevant initial value problems.
Both modelsare formulated by means of differential inclusions. We consider alternative formulations which are better suited for numerical purposes: a) Standard equations of the motion completed by implicitly defined constitutive relationships.
This leads to solving differential-algebraicequations (DAEs). b) Filippov systems of ordinary differential equations (ODEs) with discontinuous right-hand sides. For a numerical solution one can use the Filippov's convex method.
We try to compare both approaches.