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Shorter product cycles, a high awareness for comfort properties on the customer side and an increasingly strict legislation with respect to environmental issues make the development of friction materials more and more challenging. In contrast to many other engineering tasks, nearly no software tools are available to the material developer, which systematically support the development process with simulations. This work focuses on the time-dependent three-dimensional heat distribution inside a pad material and shows, how heterogeneous material mixtures can be modeled, such that a prediction of non-stationary temperature fields becomes possible. In this context, a strategy is suggested, how the thermal interaction between pad and disk and the aspects of energy dissipation and heat partitioning can be described appropriately.

Widely known is the fact that friction and wear characteristics of disk brakes are subject to pronounced temperature dependencies. For systems with organically bound brake pads, many thermally induced material changes can occur, ranging from degassing of the phenolic resin binder up to degradation of fibers and melting of metallic components. All these effects modulate the surface structure between pad and disk. They are a major contributor to friction layer dynamics [1] and directly influence the system's performance. Concerning the calculation of contact temperatures in disk brakes, several attempts have been made in the past. Most of them, however, use drastic assumptions (e.g. homogenous materials and ideal contact), which limit the results to qualitative approximations [2]. Recent studies already include the multi-material structure of brake pads. These give indications on how material mixtures must be changed, in order to modify contact temperatures into a certain direction [3].

Brake pad materials in today's commercially marketed vehicles are usually complex phenolic resin based composites with numerous ingredients. Since the abandonment of asbestos fibers, different material classes evolved in Europe (low steel), North America (semimet) and Asia (NAO), which specifically meet the requirements of the respective market [ 1 ]. For these complex materials, no a-priori prediction of friction and wear performance is possible today [ 2 ]. Research over the past decade revealed that friction power and wear debris are interrelated [ 3 ] and that the topography of the friction layer shows a very rich dynamic [ 4 ]. The respective processes can be well described with a family of dynamic friction laws, which is suitable for the description of AK-Master test results [ 5 ], as well as for the understanding of history dependent high frequency effects.

Over the last two decades, intensive research in the field of innovative brake rotor materials for high performance vehicles has been done. Due to the market demand for lightweight components with high strength even at elevated temperatures, most new concepts are based on fiber-reinforced materials [1]. The most prominent concept is a silicon carbide matrix material with embedded carbon fibers (C/C-SiC), which penetrated into the market for brake rotors in 2000 [2,3]. Such carbon ceramic brake rotor systems (CKB) have already been made available for a wide range of premium sedans, SUVs and sports cars. In terms of tribology, these rotors pose new challenges for an understanding of the relevant friction phenomena in the boundary layer, as well as for suitable formulations of brake pad materials. The brake system's macroscopic tribological performance with such pads is determined by a closed-loop interaction between heat, wear and sliding resistance on the micro scale.

The vision for the future automotive chassis is to interconnect the lateral, longitudinal, and vertical dynamics by separately controlling driving, braking, steering, and damping of each individual wheel. A major advantage of all wheel drive electric vehicles with four in-wheel motors is the possibility to control the torque and speed at each wheel independently. This paper proposes a traction controller for such a vehicle. It estimates the road's adhesion potential at each wheel and adjusts each motor voltage, such that the longitudinal slip is kept in an optimal range. For development and validation, a full vehicle model is designed in ADAMS/View software, in co-simulation with motor and control elements, modeled in MATLAB/Simulink.