Numerical Analysis of the Effect of Train Speed and Axle Load on Rail Fastening System Components for Heavy Haul Track

With the ever-increasing demand for heavy haul and high speed trains the track, especially fastening system, suffers a lot and is experiencing unexplainable failures which reduce the life of the entire track. Although the numerous researches have been conducted on fastening system for different reasons (many concentrated on one component), few researches have been conducted on effect of train speed and axle load on all components of the fastening systems. In this research an ANSYS Software is used to numerically analyze the effect of speed and axle load for heavy haul on fastening system components. Different speeds and axle loads are considered. It is shown that by increasing the ratio of the lateral to vertical load (L/V ratio) the deformation increases at high rate compared with the increments in the speed. The results show that when this ration increases from 0.1 to 0.5, by considering the speed of 100 km/h for 25t axle load, the rail deformation increases 299.5%, railpad 115.5%, abrasion plate 69.1%, rail clip 162.1%, bolt 117.4 %, shoulder 223.8% and top of the sleeper 55.1 %. It is also shown that by increasing the speed from 80km/h to 160km/h the deformations, in all fastening system components, increase to an average of 32%. Increase of axle load from 25t to 40t causes the deformations to increase up to 13% compared to the increase of speed. It means that the increase of axle load is more effective compared with the increasing speed. The results are expected to add on more understanding of the mechanical behavior of fastening systems when subjected to different loading scenarios.