The train transport is often confronted with greatly repeated changes in scope, vehicle travel well-being and transport safety because of the adjustments of Wheel and rail profiles. These problems are frustrating and threatening. Thus, there is a requirement for an approach to predict the wear of Wheel/rail to tackle these problems. A new theoretical ground is broken through the build-up of a modified structure motivated by dimensional analysis to predict the growth of the Wheel profile by drawing on Li et al. ’ s seminal work on Wheel profile. The principal difference between the current research and Li et al. ’ s work is the incorporation of additional wear profile parameters of fatigue strength and design factor. A framework is then developed for damped and undamped vibration circumstance with simulation results. The suggested approach could comparatively predict the needed parameters with the advantage of a wide scope of parametric coverage. The novel element of the paper is the unique way of predicting the desired parameters in a wider range of parametric observations. The probable use of the method is the state functional railway corporations in developing countries.

High-speed railway tracks require high quality track and accurate maintenance, but rail irregularities in main lines are inevitable. These irregularities are important sources for dynamic excitation. For the safety of trains at higher speed, the size of irregularities must be limited. In this paper, according to the Railways Standards, the Wheel load reduction (WLR) ratio is introduced. Based on this ratio, the limitation for rail irregularity size is presented. Dynamic responses of track due to “V” shaped irregularity and rail corrugation is treated. A case study of rail corrugation is presented by real data measured from the Northeast district of Iranian railways.

This paper deals with the threshold radius that warrants the use of single restraining rail for transit and railroads. Different railways use different threshold radius from 91m to 365m to provide restraining rail. These threshold figuresare probably experience driven choices. The need for restraining rail may be related to a so-called derailment alarmcoefficient of 1. 2 sustained over 2m length (According to UIC leaflet 518 a safe maximum value of Y/Q ratio of 0. 8over the length of 2m is recommended) but it needs a Wheel/rail interaction software to estimate derailment coefficient. The author is not aware if it has been done for this purpose. A quick and simple assessment method is developed here. A restraining rail reduces the angle of attack (AOA) to reduce the likelihood of Wheel climb derailment and to reducewear provided it is installed close enough to the inner (lower) rail to prevent flange contact with the outer (higher)running rail. Angle of attack depends on Wheel base, curve radius and free play. The threshold radius is formulatedby considering these three parameters. An assumption made to derive the equation is that twice the AOA on tangenttrack due to free play is a critical AOA on circular curves to warrant a restraining rail. The assumption is validatedby comparing the threshold radius obtained by the formula with real world examples. It is also shown that curvatureresistance of the threshold radius is too high to warrant a restraining rail. If the radius of the curve is less than thresholdradius then the restraining rail needs to be extended into the spiral up to a point where the radius matches with thethreshold radius. A formula substantially based on current practice is given to determine the extension of singlerestraining rail into the spiral subject to a minimum requirement.

This paper deals with the modeling of a vertically coupled vehicle-slab track using finite element method. The slab track system is represented by a two layer Euler-Bernoulli beam model including rail and concrete slab. The vertical stiffness of track bed is assumed to be random variable using Monte Carlo simulation. The vehicle is simplified as a multi-body system with 10 degrees of freedom. The accuracy of the simulation is verified by deterministic and random approaches as well. Sensitivity analyses on the various parameters such as slab thickness, coefficient of track bed stiffness, vehicle velocity are performed. It is demonstrated that the uncertainty in track bed stiffness has a major effect on rail and slab deflections. From a practical point of view, the obtained results of the present study can be utilized efficiently in the analysis and design of slab track systems.

One of the important features of an interconnection network is its ability to efficiently simulate programs or parallel algorithms written for other architectures. Such a simulation problem can be mathematically formulated as a graph embedding problem. In this paper we compute the lower bound for dilation and congestion of embedding onto Wheel-like networks. Further, we compute the exact dilation of embedding Wheellike networks into hypertrees, proving that the lower bound obtained is sharp. Again, we compute the exact congestion of embedding windmill graphs into circulant graphs, proving that the lower bound obtained is sharp. Further, we compute the exact wirelength of embedding Wheels and fans into 1, 2-fault hamiltonian graphs. Using this we estimate the exact wirelength of embedding Wheels and fans into circulant graphs, generalized Petersen graphs, augmented cubes, crossed cubes, Möbius cubes, twisted cubes, twisted n-cubes, locally twisted cubes, generalized twisted cubes, odd-dimensional cube connected cycle, hierarchical cubic networks, alternating group graphs, arrangement graphs, 3-regular planer hamiltonian graphs, star graphs, generalised matching networks, fully connected cubic networks, tori and 1-fault traceable graphs.

The main design criteria of ballasted railway tracks include rail deflections, rail bending stresses, rail Wheel contact stresses, sleeper bending moments and ballast sleeper contact pressures. Various criteria have been defined for the design of ballasted railway tracks due to the various mechanical properties of track components and their complex interaction. Therefore, the railway track design is a difficult and time-consuming process. These complications highlight the need to focus attention on the necessity of a thorough investigation into the effect of the track and rolling stock parameters on the design criteria. In an attempt to overcome this problem, a sensitivity analysis of the main railway track design criteria was conducted in this study. Consequently, the roles of track and rolling stock parameters (including track modulus, sleeper spacing, train speed and axle load) in the design of railway track were investigated for various track design criteria. The research findings provide new and practical suggestions in the analysis and design of ballasted railway tracks.