The purpose of this research is to identify the thermomechanical factors to be considered in simulation of the braking process, calculation of the distribution of the contact pressure, and temperature and obtain wear patterns for the disc brake system in operation. The factors affecting the temperature distribution and stress-strain state of disc brakes in railway vehicles are analyzed. The mutual influence of the thermal problem and contact problem was considered. The results of the numerical simulations for the finite element models can be used in optimizing the disc brake design in order to reduce wear and provide higher reliability of the braking system. The investigation showed that the displacements due to thermal deformation affected the distribution of the contact pressures significantly. The contact pressures, in turn, define the temperature distribution at the surface of the brakeblock and the brake disc; therefore, the thermomechanical and tribological phenomena should be considered simultaneously. Peak values of the contact pressure at the brakeblock surface ranged from 1.9 to 12 MPa in the considered cases. These values significantly exceed the nominal contact pressures of pnom = 0.7 MPa. This resulted in high temperatures (over 400 °C) at the contact surface. Therefore, the effects of braking speed and temperature on the value of friction coefficient and thermophysical properties of the brakeblock lining material should be considered in the analysis. The brakeblock lining shape distorted due to thermal deformation and wear. The average value of wear after one complete braking reached 12 µm. The wear at the surface was not uniform and depended on the nominal contact pressures and temperature distribution. This should be taken into account before starting the simulation of the next braking. The obtained wear patterns as well as distributions of the contact pressure and temperature provide important information for optimizing the brakeblock design and can be used by the manufacturer for improving efficiency and lifespan of the braking system.
Finite element analysis of railway disc brake considering structural, thermal, and wear phenomena
2012
16 Seiten, 21 Bilder, 3 Tabellen, 21 Quellen
Aufsatz (Zeitschrift)
Englisch