Comparative analysis of methods for the investigation of brake wear particles emission of railway vehicles

Abstract

The braking systems of railway vehicles are a key element for the safe and efficient operation of trains. Although according to official reports, the railway sector contributes less than 1% to total PM emissions in Europe, PM concentrations in enclosed spaces of underground railways are of great concern due to the confined nature of these spaces. Numerous studies have identified brake wear as the primary source of these emissions, as particles are generated during the braking process, under conditions of intense heating and wear in the contact zone between brake pads and discs. The aim of this paper is to critically analyze previous experimental studies to arrive at the most efficient and appropriate methodology that would provide knowledge about the mechanisms of particle generation caused by wear of brake pair elements in order to find ways to control the number and size distribution of particles in the air. In this regard, the advantages and disadvantages of various field tests with full-size brakes, laboratory tests on real brakes and reduced-scale brakes, as well as laboratory tests with a pin-on-disc machine were analyzed.