Veröffentlichungen

Friction brakes are used to ensure the deceleration of motor vehicles. As a result of tribological mechanisms, brake disc and brake pad wear occurs, which also leads to the emission of particulate brake dust. Particulate emissions from powertrain systems are becoming increasingly important, particularly due to their special chemical-physical properties. In the present study, brake emissions are characterized as a function of the tribological formation mechanisms and the operating conditions of the wheel brake. The development of suitable test cycles, the requirements for a laboratory test environment and a target-oriented selection of the metrological framework conditions are addressed. Finally, the challenges that arise during the performance of on-road tests (RDE) are described and evaluated.

In this work, a dissimilar copper/aluminum lap joint was generated by force-controlled hybrid friction diffusion bonding setup (HFDB). During the welding process, the appearing torque, the welding force as well as the plunge depth are recorded over time. Due to the force-controlled process, tool wear and the use of different materials, the resulting data series varies significantly, which makes quality assurance according to classical methods very difficult. Therefore, a Convolutional Neural Network was developed which allows the evaluation of the recorded process data. In this study, data from sound welds as well as data from samples with weld defects were considered. In addition to the different welding qualities, deviations from the ideal conditions due to tool wear and the use of different alloys were also considered. The validity of the developed approach is determined by cross validation during the training process and different amounts of training data. With an accuracy of 88.5%, the approach of using Convolutional Neural Network has proven to be a suitable tool for monitoring the processes.