Overview of methods to identify the static normal wheel-rail contact

Abstract

Determining the shape and size of a wheel-rail contact area is required to calculate fatigue and wear of wheel and rail. Fatigue and wear are influenced by high pressures of up to 1000 MPa that act on the small contact area of approximately 1 cm². One problem in identifying the contact patch is the inaccessibility of the contact point. Therefore, numerical and experimental methods have been applied to identify the shape and size of the contact area in the static wheel-rail contact. Here, we summarize and compare methods to identify the static wheel-rail contact area, in particular the Hertzian calculation, the use of carbon paper, the use of pressure measurement film, the finite element method, the use of ultrasonic testing, and a semi-Hertzian method called STRIPES. Our review revealed that several methods exist to determine the static wheel-rail contact, which were introduced as well as results of some research projects. However, the partly incomplete description of methods studied impeded a detailed assessment of the results. Furthermore, due to the non-comparable parameters applied in the different studies, it was impossible to contrast the results and methods presented in the different publications. Hence, it is recommended that future results in the field of static wheel-rail contact should be directly contrasted with a detailed finite element model. This proceeding will allow to directly compare different methods on the bases of finite element analysis and thus the identification of a method for each situation.