Analysis of the Performance of Disc Brake System of Addis Ababa Light Rail Transit Using Temperature and Coefficient of Friction as a Parameter

Abstract

Most of railroad passenger vehicles in the world equipped with disc brake system which is mounted either on the wheel for (wheel mounted) or axle on the bogie frames for (axle mounted). A disc brake is a device which is used to stop or reduce the motion of vehicles. The braking performance of the train is one of the most important factors that affect the traffic and running safety of the vehicle. Among many factors, braking performance of trains is mainly affected by temperature and µ (between brake disc and pad). The main purpose of this study is determination of nodal temperature and friction coefficient, considering different loading and operating conditions, necessary to verifying safety requirements for the movement of trains. Disc brake is modeled on Solid Works 13.0, then simulation was followed using Multi-physics ANSYS workbench 14.5 Version. The thermal transient analysis of disc braking system is performed to evaluate under service and emergency braking conditions independently for selected stations. A comparison between analytical determination of µ and Ansys analysis results shows that, the performance of the disc brake is highly affected during emergency braking conditions due to minimum stopping distance and delay time. The analysis result shows, compare to the 3 stations, the maximum nodal temperature is 413.88°C at station Meri/CMC 2 which is much less than from the allowable values of 800°C. The results obtained by the simulation are satisfactory compared with those of the specialized literature Hence, a good suggestion will be given on the vehicle travelling speed based on the performance on each braking conditions where if results is obtained above the allowable value.

The Wear of Cutting Pellets Coated with TiAlN During Machining of a Cobalt Superalloy (FSX-414)

“…Among the many factors influencing the tribological system in metal cutting, the tool performance is mainly affected by temperature and the coefficient of friction µ (Tool Interface / piece) [14]. Developed to be used at high temperature, superalloys which are based on alloys containing iron, nickel or cobalt have high mechanical properties at high temperatures and low chemical reactivity (inoxidability).…”