4. Track geometry and vehicle-track loads & damage

Smooth running and a good curve negotiation of the vehicle are fundamental to reduce the quasi-static and dynamic loads on the vehicle and on the track and consequently to reduce the running surface damage and/or the vehicle-track components fatigue : they depend on the vehicle design, but also on track and wheel-rail profile health, which change with mileage. The mutual impact of vehicle and track in the deterioration of the nominal design characteristics of the track and of the vehicle are subject of very complicated theoretical – empiric models and are out of our scope. Nevertheless the basics of running surface damage (wear and rolling contact fatigue (RCF)) will be described, considering their big impact on running safety, ride comfort, fatigue loads, noise, and vibration on the Life Cycle Costs (up to 30 % of the vehicle maintenance costs are related with wear and running surface...