Author/Authors :
sattari ، sajjad Department of Mechanical Engineering - Islamic Azad University, Najafabad Branch , saadat ، mohammad Department of Mechanical Engineering - Islamic Azad University, Najafabad Branch , Mirtalaie ، Hasan Department of Mechanical Engineering - Islamic Azad University, Najafabad Branch , Salehi ، Mehdi Department of Mechanical Engineering - Islamic Azad University, Najafabad Branch , Soleimani ، Ali Department of Mechanical Engineering - Islamic Azad University, Najafabad Branch
Abstract :
Railway brake system is a very complex process with great effect on traffic safety. This complexity originates from some different events in types of mechanical, electrical, thermal, etc that occur by braking. Main effective factors on performance and brake system function are braking force, speed of the vehicles, braking/stopping distance, condition of railway, and environmental parameters. In this paper, a freight rail transportation system is modeled using universal mechanism (UM). The under analysis train includes two electric locomotives and 50 open wagons and the braking system is simulated in-service braking mode. First, the parameters of coupling force, braking force, brake cylinder pressure, braking distance, and speed (per initial speed of 30 m/s) are examined and evaluated, then the effect of friction coefficient (between wheel-pad) for different types of pads, maximum braking force, and maximum coupling force were evaluated. One of the results showed that application of two different materials, gray-iron, and composite, as a brake pad: (i) does not have a significant effect on the maximum coupling force, but (ii) the maximum braking force on the composite material in 1-2 wagons is about -120 kN and in 3-52 wagons is about -95 kN, while these values in gray-iron are about -40 kN and -28 kN for 1-2 wagons and 3-52 wagons, respectively.
Keywords :
Railway , Braking system , Universal mechanism (UM) , Braking force , Brake cylinder pressure
