Investigation on reverse detail fracture in high rails on curved tracks

This thesis investigates the cause of reverse transverse defects (RTDs) found in high rails on curved  tracks.  A  parametric  study  on  the  role  of  bending  stress  on  RTD  initiation  has  been investigated  using  a  finite  element  model.  Reverse  bending  stresses  have  been  found  to  be inadequate to initiate a crack at the rail lower gauge corner. Microstructural examinations of flow  lips  of  ex-service  high  rails  from  curved  tracks  have  been  conducted  along  the transverse and longitudinal rail sections. Cracks have originated from the brittle white etching layer and at the flow lip caused by uneven plastic flow of material.