The reduction of particulate emissions is of increased importance in our society. In 2013 the road transport contribution to PM10 and PM2.5 emissions in the EU region counted for 11% and 16% respectively of the total emission. Related to these road transport emissions, the non-exhaust fraction equals almost the 50% of the exhaust one. One major contributor to the non-exhaust fraction is wear particles generated from automotive disc brakes. Despite that the pad-to-rotor contact in disc brakes is an important non-exhaust contributor; a lot of research questions remains about the wear mechanisms that are dominating the production of particulate emissions.
This paper discusses the use of FEA to simulate wear and temperature distribution in a pin-on-disc tribometer, especially design for particulate research. The aim is also to estimate important contact parameters, such as contact temperature and contact pressure distribution, which cannot be obtained directly from the measurements.
A FE-model of the pin-on-disc tribometer has been developed in the finite element package ANSYS v15. The model includes the 3D geometry of the test specimens and the specimen holder. Transient thermal analysis is used to simulate the temperature distribution in the system due to frictional heating in the sliding contact between the pin and the disc. Furthermore, a customized procedure has been implemented to simulate the wear of the pin. To validate the FE-simulation, the result is compared to experimental results for a typical pad-to-rotor material combination found in European braking systems.
The result shows that the models can be used to simulate the frictional heating of the system and makes it possible to estimate the heat partition between the pin and the disc, as well as the contact temperature during a test. It is also explained the evolution of wear and deformation during time and their contribution to the pin displacement.
Giorgio Valota, Stefano De Luca - Brembo S.p.A. Anders Söderberg - KTH Royal Institute of Technology