Effects of Mechanical Wheel Slide Protection Devices Action on Railway Vehicles Braking Process

Abstract

The paper investigates the effects of mechanical wheel slide protection devices (WSPD) on the braking capacity for coaches equipped with disc or cast iron block brakes. Decelerations and jerks, that affect the passengers comfort, are also analyzed. An original simulation program, based on experimentally determined air pressure evolutions in brake cylinder is used for this purpose. Results of numerical simulations show that in the case of repeated actuations of mechanical WSPDs, disc brake vehicles are more affected in terms of braking capacity. Regarding jerks during braking actions, in both normal and low adhesion conditions, vehicles equipped with high power cast iron block brake with two pressure levels prove to be more affected.

Dynamics observer for the longitudinal behavior of a wheelset on a roller rig

“…In addition, the forces in the wheel-rail interface are F F F j = [F j,x ; F j,y ; F j,z ], with the longitudinal creep force F j,x and the normal force F j,z . The other parameters of (1) and (2) are listed in railway configurations and the variations are taken from the technical specification for interoperability of the European Union Agency for Railways. 9 Regarding the wheel load the variation describes the difference between a wagon with and without passengers but neglects the dynamic wheel load deviation due to track irregularities.…”

“…The trade-off between safety, comfort, and wear is an essential aspect of many research activities that deal with railway technology. 1,2 Regarding the longitudinal railway dynamics, the wheel-rail interaction strongly influences all of the three criteria. Current traction and braking systems like wheel slide and skid protection already ease the trade-off to a certain extent.…”

About the influence of wheel slide protection devices action on longitudinal dynamic of trains

“…3). For the sake of illustration, it is to notice that the stopping distances resulted (following [13]) by simulations for individual vehicle are 915 m, respectively 988 m.…”

“…Considering the vehicles designed for a specific running speed V max ≥ 160 km/h equipped with disc brakes, the brake force is described accounting the dependency on instantaneous air pressure in brake cylinders p BC and the wheel-rail adhesion coefficient in normal conditions [8,13]:…”

Thermoelastic Analysis of Disk Brakes Rotor

“…The brake disk consumes the major part of the heat, usually grater than 90% [37], by means of the effective contact surface of the friction coupling. Considering the complexity of the problem and the limitation in the average data processing, one identifies the pads by their effect, represented by an entering heat flux (Figure 3).…”