the track stiffness experienced by a train will vary along the track. sometimes the stiffness variation may be very large within a short distance. one example is when an unsupported sleeper is hanging in the rail. track stiffness is then, locally at that sleeper, very low. at insulated joints the bending stiffness of the rail has a discontinuity implying a discontinuity also of the track stiffn...

Rail inspection is an important task in railway maintenance. The speed and loads of trains have been increasing greatly in recent years, and these factors inevitably raise the risk of producing rail defects. Mainly the discrete surface defects impact the riding quality and safety of a railway system. However, it is a challenge to inspect such defects in a vision system because of illumination i...

Rail joints have a shorter service life than most other railway track components. The discontinuity between rail ends turns the rail joint into a weak spot, and consequently, into a track component demanding more frequent maintenance measures, which result in high maintenance costs. Moreover, difficulties are often found when assessing the damage condition of rail joints since damage conditions...

Ride comfort is one of the most important dynamic performance characteristics of railway vehicles and it is affected by various factors such as vibration, noise, smell, temperature, visual stimuli, humidity and seat design. Evaluating ride comfort is not simple because all these factors must be considered simultaneously. In general, vibration, which originates from vehicle motion, is taken as t...

Wheel/rail contact simulation is one of the most complicated problems in the modeling of railway vehicles. The wheel/rail interaction plays a unique role in rail vehicle dynamics. In this paper, the dynamic response of the wheel on irregular rail track is analyzed with analytical approach using the method of Multiple Scales (MMS). The Hertzian contact theory is used to obtain the relationshi...

The identification of infrastructure critical to regional rail freight operations has many implications. Primarily, such a process informs policy-makers and directs funding to areas of high importance and/or greatest need. For the Chicago Metropolitan Agency for Planning (CMAP), analysts at Cambridge Systematics developed an infrastructure identification process designed to evaluate which key a...

the ability to perform rolling contact fatigue (rcf) experiments in wheel–rail material is provided by a new small–scale test rig, manifesting the actual dynamic behaviour of the railway system. in this paper, a multi-body dynamics (mbd) model is proposed, simulating the vibration behaviour of the prescribed rig. the new testing facility is modelled using a three-dimensional model of the vehicl...

We develop a model to determine the optimal structure and size of a rail car fleet at a chemical company under uncertainty in demand and travel times as well as substitution between rail car types. First, we formulate an MILP model that accounts for the substitution relations between the types and minimizes the total direct rail car cost under given rail car availability constraints and a prede...