A numerical and analytical study of the stress field generated by the contact between a rail and a wheel

Abstract

This article presents a study of the contact stresses between a rail and a wheel, in order to understand the mechanism related to this application. When two bodies, regardless of their forms, touch each other due to an external load, both suffer a slight deformation on the contact surface, creating a stress field in this area, and the complete comprehension of this phenomenon is fundamental to calculate critical stresses and to prevent possible failures. This article approaches this topic in two different manners: one analytical, using Hertz equations; and another numerical, using the FEM software Ansys. The results obtained from both approaches are compared, and the model can be validated. The results show that when these two cylindrical bodies are pressed against each other, a small rectangular area is created, and the highest normal stresses are found exactly where the two elements touch. It is seen that the maximum shear stress is found along the depth of the body and is the most critical for the appearance of cracks. The results from this work are in good alignment with reality and they can be used to predict possible failures and behaviors in real applications.