This working field has been initialized by a joined project of Knorr-Bremse GmbH, Siemens Mobility and our institute.
The goal of this project was to understand potential vibration mechanisms of brakes in high-speed trains. The study comprises a comprehensive multibody simulation study and its comparison to experimental results at the test rig of Knorr-Bremse in Munich, see figure below.
It is a result of the project that the on-set ofa certain type of brake vibrations can only be explained if the thermoelasticity of the brake disc and system dynamics of the whole brake system including its mounting in the bogie is taken into account.
In cooperation with Knorr-Bremse, a succession project, scheduled for three years, has been defined in order to develop a brake model that is capable to explain this specific vibration behaviour. The model will use the so-called modal multifield approach to describe the coupling of the thermal andthe mechanical field of thebrake disc and as well will take advantage of the ALE-description, that enables an easy brake-disc/pad contact formulation. The innovative simulation environment, whose first draft originates from a Simpack/Modelica project with Daimler and is related to the ITEA2 Modelisar project, will combine the advantages of the multibody tool Simpack and the multi-domain modelling language Modelica.
Besides the solution of the described specific problem, the results of this project will as well be introduced into the commercial Modelica FlexibleBodies Library and the new Modelica Multifield Library, that is developed in the ITEA2 EuroSysLib project. This concerns in particular the rotor-dynamical ALE formulation and the modal multifield approach.
Side view of the Knorr-Bremse brake test rig (photo and multibody model)