In the coming years, the Dutch rail infra provider (ProRail) wants to develop the technique of dynamic stiffness measurements along the track in order to characterize the ‘dynamic performance’ of – finally – the entire Dutch network. The technique has been developed to some extent by the Swedish Bahnverket and some other parties, but ProRail/TU Delft wants to make it suitable for specific circumstances and aims in the Netherlands. The main responsibility of Mehran will be the development of this technique in cooperation with Swedish parties who will do test runs in the Netherlands, starting on a local scale and ending on a network scale. For his current research project, Mehran will mainly focus on the track dynamics and he will be responsible for developing different analytical and numerical models describing the dynamic behavior of railway track. Models with different degrees of complexity and with different aims, ranging from very simple to more sophisticated models, will be employed. The final aim of the project is to assess the long-term degradation and environmental vibration radiation for railway tracks, caused by cyclic loading from trains.
Both environmental vibration radiation from train operation and long-term track degradation are governed by the ‘flow’ of mechanical energy through the railway super- and substructure. This flow consists of three elements: (1) input, provided by the rolling stock moving along and interacting with the structure; (2) throughput, with a transmitted and an absorbed part, the latter governing local degradation; (3) output in the form of vibration radiation.
Mehran will be working on characterization and control of this energy flow, which is vital for limiting vibration hindrance and track maintenance.