Studying the load of composite brake pads under high-temperature impact from the rolling surface of wheels

Abstract

The object of the research is the processes of thermal stress, perception and redistribution of loads by the brake composite pad during braking of the car in operation.
 In the current conditions, wedge-dual wear of composite brake pads is observed in the braking systems of freight cars, the feature of which is the deterioration of the braking efficiency of freight trains. With this type of wear, both an increase in the load on the brake pad and an "underuse" of the amount of pressure on it can occur.
 A comprehensive thermal calculation was carried out for composite brake pads with uniform and wedge-dual wear. The results of the calculation showed that the amount of pressure on an abnormally worn pad is 23.3 % less than that acting on a pad with nominal values.
 It has been proven that the change in the pressure force on the composite pad with different values of the wear parameters during braking leads to a change in the braking force that occurs between the wheel and the rail during braking.
 The calculation of the strength of the composite brake pad with wedge-dual wear was carried out.
 The obtained results will make it possible to develop measures to modernize the elements of the brake lever transmission of freight cars.
 The field of practical use of the obtained results is car-building enterprises. The conditions for the practical use of the results are the brake lever transmissions of carriages of cars with a gauge of 1520 mm.
 The conducted studies prove the negative impact of wedge-dual wear not only on braking efficiency, but also on the strength of brake pads. This makes it necessary to create measures aimed at its elimination, which will contribute to increasing the level of train traffic safety and significantly reducing the operational costs of maintaining freight cars

The Service Life Prediction for Brake Pads of Freight Wagons

“…Equation ( 1) is determined with k > 0 and k < -1 , where b < a < c and b ≥ 0. For Equation (1), the distribution function has the form [23][24]: point of view, considerable theoretical work is being done to study the temperature characteristics of composite brake pads used in wagons under different operating conditions at various speeds [19][20].…”

Analysis of Asymmetric Wear of Brake Pads on Freight Wagons despite Full Contact between Pad Surface and Wheel

“…The operation problems and appointment of the terms of maintenance and repair of freight-wagon brake systems related to the elimination of the phenomenon of non-normative wear of brake pads have not yet been sufficiently studied. From this point of view, the scientific and technical studies dedicated to this problem have been carried out for many years as part of the research and development work of the authors' team [11][12][13]. One way or another, the successful solution to this problem relates to the improvement in the mechanical brake system of freight wagons.…”

Reducing Traction Energy Consumption with a Decrease in the Weight of an All-Metal Gondola Car

“…However, in all works, composite materials have been used in passenger cars. In addition, the use of composite materials in gondola cars [45][46][47] has been complicated by the manufacturing technology.…”