Fatigue behaviour of railhead material damage of insulated rail joints due to cyclic wheel loadings

A 3D finite element analysis (FEA) is carried out on IRJs to focus on damage analysis of sub-surface railhead material for endpost materials: fibreglass, nylon 66, and polytetrafluoroethylene. A cyclic vertical wheel load up to a total of 2000 cycles in non-Hertzian pressure form is applied at the wheel/rail contact patch on an IRJ. The longitudinal damage parameter is considered to rank the sub-surface railhead damage. It exhibits a new pattern described as ‘vertical flat type’ for a depth up to 8mm initially and, as the cyclic loading increases, the flat pattern damage changes to an ‘inclined flat type’ pattern.