Investigation of the Influences on Heat Crack Propagation in Truck Brake Discs
Heat cracks in truck brake discs not only cause increased maintenance costs due to the earlier exchange of the discs, but also pose a threat during regular operation of the truck if they are not detected early enough. Often enough, the development time of new brake discs for trucks increases due to heat cracks that occur on test parts, as brake discs that tend to suffer from heat cracks cannot be released for production. Basic findings about the reasons for the development of heat cracks in truck brake discs and their growth behavior exist, which must be verified and thoroughly considered.
Thus, the influences on the initialization and propagation of heat cracks are researched at FZD. Aims of this research are a deeper understanding of the proceedings that induce cracks during the alternating thermo-mechanical stress that acts on the brake disc as well as the development of simulation models to predict the development of cracks and thus prevent it for the most part.
In the course of the project, investigations are conducted with the help of numerical simulations as well as by tests on an inertia dynamometer. Furthermore, material-specific questions are answered in cooperation with the Center for Structural Materials.
This project focuses on modeling the brake disc material as well as the material fatigue and crack growth in finite element simulations. Additionally, the insights gained by extensive test series on the dynamometer are fused with the results of the finite element model. After the end of the project, the weighed influencing parameters and a model understanding of the initialization and growth of heat cracks should be derived, which were sufficiently validated through test results, in order to forecast the growth of heat cracks.
This topic is researched at FZD in the course of a research assignment in cooperation with the Center of Competence Air Disk Brake of Knorr-Bremse SfN GmbH.