The mechanical components of the rail joint assembly are susceptible to various failure modes

The mechanical components of the rail joint assembly are susceptible to various failure modes. Some common failure modes include plastic ratcheting or shelling of railhead top surface, bolt looseness, delamination of end part of rail and joint bar, end post crushing and joint bar cracking, fretting damage on the joint parts and on rail due to the relative oscillatory movement of small amplitude that may occur between two contact surfaces subjected cyclic load4.
Rails are produce in fixed lengths and need to be joined end-to-end to make a continuous surface on which trains may run.
Rail joints are the most important structural link in a railway track for electrical signal purposes and to create discontinuities in the running surface of the rails. A wide range of end post thickness of rail joints are from 4 mm to 15 mm was found. These discontinuities produce different type of static and dynamic stresses on the running surface .These stresses on the rail head produce weakness on the joint and rail end. They cause different type of failures at the rail joint compare to the normal rail. Based on other country experience, the following failures mode is at joint: – delamination of end part of rail and joint bar, broken joint bar and looseness of the bolt, fatigue wear of rail end due to repeated loading of a surface., fretting damage on the joint parts and on rail due to the relative oscillatory movement of small amplitude that may occur between two contact surfaces subjected cyclic load. Rails are produce in fixed lengths and need to be joined end-to-end to make a continuous surface on which trains may run. The main types of rail joints are welded rail joint and bolted rail joint5-7.