Resource Estimation of Freight Car’s Brake Pads in Operating Conditions

Purpose. This research is aimed at substantiation and development of the correct for practical use model of service life exhaustion of brake pads of freight cars based on mass inspections of their wear using the elements of the statistical conclusions’ theory. Methodology. Production research conducted in several stages, allowed identifying and accumulating sufficient statistics on the malfunctions, failures or defects of the elements of the brake rigging. Statistics on determining the service life of composite brake pads before their complete failure were carried out for a typical and modernized design of the brake rigging of freight cars. The well-known provisions of the theory of statistical conclusions, which are applied to technical brake systems of units and elements of freight cars, were used as research methods. Findings. Empirical characteristics are obtained as a result of current inspections of wear of composite brake pads of brake rigging. This made it possible to achieve more reliable results from the law of random variables distribution concerning the wear of composite brake pads – to limit the service life of pads on the run under conditions of their safe operation. The proposed model of the density distribution function of random variables for composite brake pads allows high accuracy estimating such an important characteristic as the resource threshold. This make it possible to predict the brake pads performance and determine the efficiency of brake rigging of freight car bogies. Originality. For the first time, a correct statistical wear model of composite brake pads of freight cars has been proposed. Based on the developed model the occurrence chronology of clinodual wear of composite brake pads and its influence on a resource of their work in operating conditions is investigated. Field research on experimental bogies of freight cars confirmed that the service life of composite pads has increased by an average of 19% for upgraded brake rigging compared to typical ones. Practical value. The obtained positive results will be taken into account in the future to solve problematic technical issues related to non-standard wear of composite brake pads in the freight cars’ bogies of Ukrzaliznytsia JSC, which will allow extending the interrepair periods.