Both the braking systems at the wheelsets, e.g. disc brakes or regenerative braking systems at the driven bogies that are the main braking devices for railway vehicles, and the mtb, which serves as an additional brake system at severe environmental and emergency conditions, rely on the fictional forces transferred between wheel and rail, and brake shoe and rail, respectively. Hence, a thorough understanding of the development of these forces, in particular in the presence of a third body layer, is the focus of this research topic. Potential cleaning effects of the rail due to the sliding friction between the mtb and the rail, and related wear shall also be understood. The local frictional contact between a brake shoe and the rail is considered without electromagnetic (attraction) forces.

Thus, the general aims of this research topic are:

• to provide a fundamental framework to examine the frictional behaviour of the available braking (sub)systems,

• to investigate and model the contact behaviour of the brake shoe rail interaction when braking over switches and crossings (variable rail geometry),

• to investigate and model the influences of an additional layer (such as sand, oil, leaves) at the contact between brake shoe-rail and wheel–rail on the frictional contact (forces) at braking,

• to employ an experimental setup for basic research and to test and parametrise the developed models.

Problem topology and model abstraction from the real system.

Problem topology and model abstraction from the real system.