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...

One of the important clinical features to differentiate benign melanocytic nevi from malignant melanomas is the irregularity of the lesion border. A careful examination of a lesion border reveals two types of irregularity: texture irregularity and structure irregularity. Texture irregularities are the small variations along the border, while structure irregularities are the global indentations ...

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...

To effectively control the horizontal vibration of high-speed elevator car system caused by factors such as irregularity guide rail and nonlinearity spring-damping in shoes, this paper proposes an active disturbance rejection (ADR) method based on fuzzy sliding mode. Firstly, considering nonlinear characteristics dynamic model is established. Then, excitation linear disturbances are summarized ...

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...

In this dissertation, we have developed computer vision methods for measurement of rail gauge, and reliable identification and localization of structural defects in railroad tracks. The rail gauge is the distance between the innermost sides of the two parallel steel rails. We have developed two methods for evaluation of rail gauge. These methods were designed for different hardware setups: the ...

Radio irregularity is a non-negligible phenomenon that has an impact on protocol performances. For instance, irregularity in radio range leads to asymmetric links that cause the loss of packets in different directions. In order to investigate its effect, the Radio Irregularity Model (RIM) is proposed that takes into account the irregularity of a radio range and estimates path losses in an aniso...

the planning of a rail transit system is a complex process involving the determination of station locations and rail line alignments connecting the stations. There are many requirements and constraints to be considered in the planning process, with complex correlations and interactions, necessitating the application of optimization models in order to realize reliable and cost-effective rail tra...