A new method for prediction and evaluation of wear on wheel and rail profiles

Both wheel/rail profiles play a significant role in the safe operations of trains. If wheel/rail rolling contact wear is defined as the change of wheel and rail profiles due to rolling contact forces (normal and tangential combined), the plastic flow may also be considered as a major form of wheel/rail wear. Although plasticity does not change vehicle behaviour, it is important for wear calculations of wheel/rail profiles based on contact stress conditions; due to plasticity, the contact patch area increases in size and the contact pressure is reduced. The final shape of wheel/rail profiles is the consequence of a combination of wear and plastic flow. That is why a conventional Multi-body software and CONTACT model using Hertzian Contact Theory cannot predict contact conditions accurately. This project seeks to provide an innovative and more economical approach to developing suitable standard wheel and rail profiles free from assumed hypotheses and to accurately evaluate wear, fatigue and plastic damage for wheels and rails under a variety of contact conditions and dynamic loads. The process for the development of wheel and rail profiles is currently limited to consideration of RCF and wear, and the progressive change in profile shape due to plastic deformation has been neglected. Optimising wheel and rail profiles also requires innovative modelling of material relocation by plastic deformation to ensure the achievement of increased fatigue life of wheel/rail materials and reduced maintenance costs. Hence, a novel analytical and numerical approach to designing profiles considering RCF, uniform and non-uniform wear and plastic deformation with material hardening of wheel and rail materials is targeted. It will also address conformal contact without the half-space assumption and a tribological aspect of friction modelling to include creep force at the contact zone. This study will include a rigorous coupled multibody dynamics-finite element simulation (co-simulation) methodology using the specialised railway multi-body software package 'Gensys' and finite element software 'Abaqus' and incorporate verification of wear modelling results with novel laboratory test data at CQU.