Research
The MERail Research Group covers a wide range of fundamental and applied research areas.
Wear of railway overhead line components
The rail overhead power line is subject to high speed sliding wear under variable load and subject to environmental contamination. In this research a series of tests are being conducted to map the wear rates experienced by the overhead line under a range of loads and pantograph speeds. Loads in the range 80-280N and speeds from 60-125mph are being investigated.
Rolling contact fatigue crack growth
Research into rolling contact fatigue failure of rails includes fundamental understanding of crack growth mechanisms and the influence of wheel loading and rail metallurgy on crack growth. To put the understanding to use, this research has been translated into predictors of rail grinding maintenance requirements.
Resilient Design (Re-Design) for counter-terrorism
In recent years transport systems and other ‘crowded places’ have been subject to terrorist attack. Sheffield leads the rail transport aspects of the EPSRC ReDesign (Resilient Design) project developing approaches to the design of crowded places that may be subject to terrorist attack, looking at ways in which the effects of such attacks can be minimised. The project has developed decision support tools and guides for how resilience to terrorist attack can be designed into a transport system in an acceptable way, i.e. without compromising everyday experience or incurring unnecessary costs.
Static wheel/rail contact characterisation using ultrasound
In this research specimens from wheel and rail sections are loaded together hydraulically and a focussed ultrasonic probe or ultrasonic array is scanned over the contact area creating a two-dimensional reflection map. The magnitude of the reflection of an ultrasonic wave at an interface can be related to contact pressure with a simple calibration procedure. Wheel tread and flange contact can be measured.
Dynamic wheel/rail contact characterisation using ultrasound
An ultrasonic pulse from an array mounted in the rail will be used to measure the contact evolution as a wheel is rolled over the railhead in this research project. It will be possible to obtain the contact pressure plot after a calibration procedure producing high resolution data, with the potential that it could be done in situ. In addition, research is ongoing to mount a flange detection sensor in the wheel.