Prof. Dr.-Ing. Georg-Peter Ostermeyer, TU Braunschweig, GERMANY

Mr. Chengyuan Fang, TU Braunschweig, GERMANY

Mr. Felix Rickhoff, TU Braunschweig, GERMANY

The frictional behavior of a tribological contact is the result of complex interactions between two bodies.

In the case of tribological high-load contacts, such as those found in brakes, wear and the associated wear particles play a particularly important role. In the last two decades, a number of papers have been written on this subject, which explain the highly complex dynamics of the friction coefficient, among other things, with the self-organization structures of the wear material in the tribocontact.

Here, particle concentrations, so-called patches, form, which act like additional contact areas in the boundary layer. Since they change dynamically, the friction performance shows similar dynamic structures.

But the ejection of wear particles is also the current focus of research. The emissions also exhibit dynamic signatures.

This work wants to present the further developed measurement technique as well as first approaches to describe the wear particle transport in the boundary layer by experiment and simulation.

Prof. Dr.-Ing. Georg-Peter Ostermeyer, TU Braunschweig, GERMANY

Mr. Chengyuan Fang, Institute of Dynamics and Vibration of TU Braunschweig, GERMANY

Mr. Guido Lehne-Wandrey, Institute of Dynamics and Vibration of TU Braunschweig, GERMANY

Mr. Malte Sandgaard, Institute of Dynamics and Vibration of TU Braunschweig, GERMANY

Mr. Alexander Vogel, Institute of Dynamics and Vibration of TU Braunschweig, GERMANY

Mr. Jacek Kijanski, Institute of Dynamics and Vibration of TU Braunschweig, GERMANY

Mr. Thomas Hillner, wenglor sensoric GmbH, GERMANY

Mr. Fabian Repetz, wenglor sensoric GmbH, GERMANY

Friction tests under controlled conditions are crucial for the understanding of the boundary layer dynamics in technical brake systems. The dynamics of the friction interface characterize the braking performance. In order to evaluate and monitor the dynamics of the friction interface, detailed insights into the friction behavior is obtained by high precision tribotesters under laboratory conditions. Especially in the low sliding speed range, specialized machines such as the Variable Velocity Tribotester (VVT) make it possible to mimic real world phenomena under controlled conditions, e.g. creep groan or COF in low temperatures.

This paper presents the wenglor sensoric 3D sensor ShapeDrive MLAS201 for measuring the pad surface between friction applications at VVT. With this device, quasi in-situ measurements with high speed and precision of the pad’s surface are attained. The 3D sensor consists of a light engine which projects several patterns onto the pad surface and a high resolution camera which can record these patterns again. The topography and intensity information of the pad surface would be stored in a point cloud file with high precision of 12 megapixels. Such information can be used to analyze the surface properties such as roughness and height. With further algorithms it is also possible to observe the change of the entire topography and in further way to determine the wear volume and analyze the contact situations.