Development of a methodology and research results for comparing the wear of friction surfaces for disc brakes of passenger cars

It was not sufficient to merely establish the amount of wear on friction surfaces in brake mechanisms for a certain period of time. The principal objective is to determine the intensity of wear on the friction mating surfaces in general, as this will enable us to evaluate the reliability of the braking systems in passenger vehicles under operating conditions. The main purpose of the paper is to substantiate a methodology for assessing the wear intensity in frictional interfaces specifically for disc brakes that are installed in passenger vehicles. The primary objectives of the research work were identified. Conducted, accordingly, is the analysis to determine the extent to which various parameters for braking vehicles influence the wear on friction surfaces in disc brakes. Our substantiation is based on observed patterns of friction surfaces wear for disc brake mechanisms. A mathematical method was developed for estimating the intensity of wear on friction surfaces in disc brake mechanisms. Devised, additionally, was a technique for experimental research involving cyclic emergency braking of a vehicle on a dry horizontal asphalt concrete road. An analytical-graphical method was adopted to simulate the wear process on the friction surfaces of disc brakes for such passenger vehicles as: Daewoo Lanos, Lada Priora, Chevrolet Aveo and Forza. Each braking cycle consists of 30 emergency braking sequences, with initial braking speeds ranging from 10 to 35 m / s. The vehicle used was fully loaded and the aerodynamic force of air resistance was taken into account. The wear intensity of the friction interface during the braking cycle was evaluated by a special criterion. This criterion was calculated as the average sum of the friction interface wear ratios (as the difference between the disc and the friction lining wear) and the corresponding braking distance at which the wear occurred. For clarity, all measurement results were presented in both graphical and tabular formats. Formulated, in conclusion, are the key findings along with the identified pursuits for future research.