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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.

In this study, the effect of the amount of short carbon fibers (SCFs) on the mechanical and tribological properties of polyester (PES) composite were investigated. Composites were produced with different weight fractions (0.5%, 1%, and 2%) of SCFs by the hand lay-up method. The flexural strength and flexural modulus of samples was studied by conducting 3-point bending tests, whereas the energy-absorbing performance was examined by performing the Izod impact test. Moreover, the wear resistance properties of samples were measured by applying a 20 N load. The scanning electron microscope was used to examine the morphology of broken and worn surfaces of specimens. Test results exhibit the flexural strength and flexural modulus of SCFs reinforced polyester composite was decreased with the increment of fiber contents. However, the same trend was not observed for the impact test. Thus, the addition of 2 wt. % SCFs onto pure polyester improves the energy absorbing of pure polyester nearly by 210%. The present study also reveals the wear resistance properties of SCFs reinforced polyester composites are indirectly related with of SCFs content. Hence, the highest wear resistance capacity was observed for PES0.5CF of about 1.51×10-3 mm3/m. Therefore, the addition of small amounts of SCFs onto pure polyester attributes significant effects in tribological behaviors compared to mechanical properties.