Crack initiation study in railway curves under coupled thermomechanical loading using finite element simulation

Abstract

This investigation employs a three-dimensional coupled thermomechanical finite element analysis to ascertain the characteristics of the initiation of cracks in railway curves. The proposed numerical simulation of wheel–rail contact aims to examine the influence of different curvature radii and slip ratios on the temperature rise, fatigue parameters, and fatigue life of crack initiation. The load history is obtained via Universal Mechanism software and utilized in the FE model. This is the inaugural investigation wherein the cyclic plastic material response, as delineated by the hardening model proposed by Chaboche and Lemaitre, and the thermomechanical coupling have been considered in the context of a curved track. Abaqus software uses numerical modeling to determine the stress fields, temperature distributions, and contact pressure during the wheel–rail interaction. To ascertain the fatigue parameter (FP) and the direction of fatigue crack initiation in the rail, the Jiang and Sehitoglu damage model is employed. The critical plane concept is used to establish the initiated crack’s direction. As the FP grows in critical conditions, the crack creation orientation moves toward the depth of the rail rather than the surface. This phenomenon may cause dangerous rail failure and should be prevented by accurately controlling the wheel–rail contact conditions. Incorporating nonlinear thermal effects into the mechanical model resulted in a maximum increase in fatigue parameters and life of 32% and 80%, respectively.