Prediction of rolling contact fatigue loci: a comparison between dynamic and a simplified quasi-static approaches

Abstract

Abstract Predicting fatigue and wear on wheels and rails is a key to find ways to improve the service life of a railway track and the rolling stock. Rails experience contact with a range of wheel profiles that will pummel their surface at different positions with different intensities. This work compares two methods for evaluating pummelling analyses for the wheel-rail interaction: simplified quasi-static model and multibody dynamics simulations. The first one is solved using the GIRAFFE program and simulates the interaction of a single wheelset with the rail in a quasi-static approach. The second one evaluates the full dynamics of a railway wagon on a track layout using multibody dynamics simulation programs SIMPACK® and VAMPIRE®. The proposal of a quasi-static model is to reduce the time and computational effort to perform a pummelling analysis and quickly evaluate thousands of cases of wheel-rail contact. Track parameters and vehicle loads of a heavy haul railway are considered for the simulations. The results showed that the quasi-static model has a good correlation with the dynamic models on tangent track sections. For the curved sections, differences were observed in the distribution of pressures due to the absence of creep forces in the quasi-static model. The comparison between the models also showed slight distinct results due to the difference in how the contact is calculated in each approach. The quasi-static approach reduced the time consuming by at least 73.4% over the multibody approach. Notwithstanding, the proposed model shows to be promising on replacing complete dynamic analysis for time consuming tasks as pummelling.