Validation of a thermo

This research deals with a numerical and experimental investigation of the vibratory frequency and the thermal response of a railway brake disc and pad under varying conditions. Railway brake systems play a vital role in passenger safety and comfort. The performance of disc brakes with regard to the dynamic effects like brake torque oscillations and brake judder depends on the contact properties and wear surfaces. Brake fading occurs due to accumulated frictional heat thereby reducing the stopping power. For an improved understanding of the complex processes of a brake system during long-term braking, a comprehensive numerical investigation is performed initially using the finite element software Abaqus for a thermomechanical and modal analysis. While the thermomechanical analysis based on the calculations of frictional heat is used to investigate the increase of temperature during braking, the contact pressure is a crucial parameter that influences the distribution of temperature both on the brake disc and on the pads. The modal analysis is used to investigate the frequency behaviour of the vibrations. Then, a simulation model of a self-energised electrohydraulic brake provides the results of brake force oscillations with regard to the observed topologies of the brake disc’s wear surface, which is measured at a full-scale test rig by an enlarged experimental set-up. In addition to the dynamic brake force, the set-up contains the online measurement of the side face run-out and the temperature of one side of a ventilated brake disc. By comparing the results of our experimental and numerical investigations, the simulation models are validated. Future research should focus on a thermomechanical analysis that considers heating, cooling, and the wear effects. A detailed implementation of the contact pressure distribution between the brake pads and disc can lead to a more precise prediction of brake torque oscillations. The achieved results can be used to improve riding comfort and resolve safety critical problems in high-speed trains