Simplified Damage Assessment Tool for Rails and Crossings Based on Standard Wear and RCF Models

Abstract

A numerical tool is proposed to simultaneously assess various damage mechanisms that are driven by contact loading. The tool transfers loads to the contact-patch level using three contact parameters: the maximum contact pressure (pmax), the creepage (c) and the contact length (2a). The local wear and RCF predictions are implemented based on existing models from the literature. The load input can originate from numerical vehicle–track simulations or manual input of the user. The assessment tool is applied for a finite element analysis of a fixed manganese crossing nose to prove its validity. The algorithm is implemented via an automated Python code, which, on the one hand enables damage prediction for track components based on standard damage models. On the other hand, knowledge of novel local contact damage models can be transferred to the scale of track components.

Wear and RCF assessment in switch rails for different materials

“…Each pmax, c and 2a parameter set defines one working point (contact load representation) on the switch rail. Secondly, the damage maps for the R350HT and 400 UHC® HSH® are determined following the approach presented in Schnalzger et al [6]. The local damage models are based on Archard´s wear model [7] as well as an RCF model for surface and subsurface cracks adopted from Ekberg et al [8].…”

“…Carter´s creep force model is applied to obtain a relation between the traction coefficient and creepage, which is required to implement the aforementioned damage models. A detailed description about the implementation process is found in [6]. Table 1 summarizes the most important system constants and assumed material properties.…”

“…The damage of the two materials is estimated and compared for the calculated loadings. The analysis is based on the approach proposed in [6],where an assessment tool is described which allows the evaluation of damage in contact loaded components. In particular, the maximum contact pressure pmax, creepage c and contact length 2a are calculated along the switch rail for the passage of different wheel types.…”