Influência do desgaste em serviço no desempenho de perfis alternativos de rodas ferroviárias

Abstract

The study of the contact between the wheel and the rail has gained importance in Rail Engineering, especially because these components represent the second and third highest material costs in the railroad, fuel being the first. It is well known that wear is the main cause of pair replacement on almost all railways. And this wear varies according to the contact conditions. Such conditions change depending on the particularities of each railway, such as speed, macrogeometry and the materials used, among others. With the constant evolution of computers and simulation programs, it is possible to predict the wear of wheels and rails, as well as the initiation of rolling contact fatigue. Thus, in order to evaluate the influence of wear on the performance and selection of new rail wheel profiles, dynamic simulations were carried out using two sets of wheel profiles, the optimized ones and those currently in use in the EFVM and EFC. The EFVM profiles showed wear distributed along the tread, due to its macrogeometry composed of sharp curves, while the EFC profiles showed more concentrated wear and the presence of false flange, due to the prevalence of tangents in this railway. The influence of wear was evaluated using indicators such as Contact Pressure, Wear and Superficial Fatigue Indexes, Fatigue Damage, Shakedown Diagram, Nadal's Criterion and Rolling Resistance. The profiles scores, considering the wear of the tread of 2 and 3 mm, were weighted according to the value of these indicators and the weights defined by LabTDF-UFES. The profiles with the highest weighted score and whose work point was within the shakedown region were suggested for field testing.