Shear stress concentrations in tramway rails: Results from beam theory-based cross-sectional 2D Finite Element analyses

Abstract

During their lifetimes, tramway networks become increasingly susceptible to mechanical damage in the form of rail fractures. Understanding the underlying reasons, and initiating appropriate countermeasures may be facilitated by (computational) modeling tools. The development of such tools calls for a sound theoretical foundation. The latter is still largely missing, as the cross-sectional shapes of grooved rails employed in tramway networks differ significantly from those of (in this regard) well-investigated railroad systems. As a first step towards closing this knowledge gap, we here report on a novel beam theory approach allowing to compute typical shear stress distributions throughout the cross sections of grooved rails. Based on classical concepts, such as Bernoulli and Saint-Venant beam kinematics, cross-sectional boundary value problems for the related shear stress distributions are derived, and corresponding solutions are obtained in the form of 2D Finite Element approximations. This way, it is revealed that practically relevant loading scenarios induce distinctive shear stress concentrations. Remarkably, the positions of the latter agree well with fracture patterns observed in situ.