Dynamic tangential contacts: Numerical description of nano-positioning devices

Piezoelectric motors using the stick-slip principle are standard technical devices. However, their physical description remains case specific and is often based on multiple empirical parameters. We will describe the method of dimension reduction and how it can be used to describe dynamic tangential contacts. Considering the positioning axis of the nano-positioning device Ramona, we will exemplarily show how this method is used. The runner is driven by six piezo actuators, rotating ruby hemispheres. Different models describing the sphere-runner interaction are presented.