Railway mobility is a very energy-efficient way of transport. This is a fact of the small rolling resistance at the wheel–rail contact. A drawback is the small coefficient of friction between these contact partners, resulting in small decelerations and possibly long stopping distances. In an emergency situation, when the train has to come to a quick stop, or if rails are wet or contaminated, braking with wheel brakes may not be sufficient. Then, (electro)magnetic track brakes (mtb), which are independent of the wheel–rail contact conditions, or devices that modify wheel–rail frictional contact conditions, such as sanding systems, are deployed to develop additional braking forces. While braking based on the wheel–rail contact has been fundamentally studied over decades, several open questions referring to sanding systems and mtbs still require fundamental research.

Aims

The aim of the proposed Christian Doppler Laboratory is, from a practical point of view, the enhancement of the braking behaviour of railway vehicles by means of better utilisation of the contact between mtb–rail and wheel–rail, with a focus on mtb–rail interaction. To achieve this ambitious aim, basic research has to be performed, in particular, to understand and model the frictional contact, the magnetic attraction, the dynamic/vibrational behaviour involved in braking, and the interaction of all braking systems.

Research Topics

The consequent structure of the CDL is depicted in Figure 1, displaying the basic research topics: Frictional Contact, Magnetic Attraction, Dynamic Behaviour, System Integration, which collectively results in improved basic understanding and therefore suggests technical improvements of modern braking systems in railway vehicles.

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