Rail Pad Dynamic Properties: A Review

Abstract

Components of the rail tracks are designed to withstand the continuous moving load and transfer it effectively to the subgrade and foundation. Apart from stresses and strains developed, the moving load also induces vibrations, causing damage to components of the rail track, amplifying already existing track defects such as head checks, corrugation, shelling and causing discomfort to passengers. Understanding vibrations and successfully isolating them is a challenging task. Rail pad plays a vital role to reduce vibration. It also attenuates the impact load of moving train and protects different components of track assembly from failure. Due to globalization and advancement in technology, freight traffic and speeds of the train have substantially increased in recent years, and thus it is now more important to understand vibration and its effects. This paper mainly discusses the dynamic properties of the rail pad and its stiffness and damping properties. First, the article gives a basic overview of the rail pad, its development over the years, fundamental theories and equations used and materials used for making the rail pad have also been discussed. Then, it reviews different experimental and numerical techniques used to determine the rail pad’s dynamic properties and effects of preload, frequency and temperature on rail pad properties. It discusses different mathematical models and equations used to couple rail pad dynamics with overall vibrations. Also, it discusses the result of considering rail pad dynamics into overall train-track coupled vibrations and how it influences the output result is being discussed and compared with experimental results.