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Polygonisation is a common nonuniform wear phenomenon occurring in railway vehicle wheels and has a severe impact on the vehicle–track system, ride comfort, and lineside residents. This paper first summarizes periodic defects of the wheels, including wheel polygonisation and wheel corrugation, occurring in railways worldwide. Thereafter, the effects of wheel polygonisation on the wheel–rail interaction, noise and vibration, and fatigue failure of the vehicle and track components are reviewed. Based on the different causes, the formation mechanisms of periodic wheel defects are classified into three categories: (1) initial defects of wheels, (2) natural vibration of the vehicle–track system, and (3) thermoelastic instability. In addition, the simulation methods of wheel polygonisation evolution and countermeasures to mitigate wheel polygonisation are presented. Emphasis is given to the characteristics, effects, causes, and solutions of wheel polygonisation in metro vehicles, locomotives, and high-speed trains in China. Finally, the guidance is provided on further understanding the formation mechanisms, monitoring technology, and maintenance criterion of wheel polygonisation.

The topic of reducing structural vibrations in the case of flexible carbodies of railway vehicles has been intensively studied, but it is still an active research topic thanks to the importance of the perspective of improving the ride comfort. However, no study has been identified in the specialty literature to feature the contribution of the vibration structural modes upon the vibration behaviour of the railway vehicle carbody. The structural vibration modes of the flexible carbodies are particularly complex, however, the first vertical bending mode holds great significance in terms of the ride comfort. This paper analyses the influence of the first vertical bending mode on the vibration behaviour in three reference points of the railway vehicle carbody in correlation with the carbody flexibility, the vehicle velocity and the suspension damping. This study relies on comparisons between the results of the numerical simulations obtained for a ‘flexible carbody’ type model of the vehicle and the ones obtained for a ‘rigid carbody’ type model. The first part of this study analyses the characteristics of the vertical vibrations behaviour of the flexible carbody based on the dynamic response of the vehicle and expressed as the acceleration power spectral density. In the second part, the influence of the vertical bending on the vertical vibrations level of the carbody is analysed using the root mean square of the vertical acceleration.

Train running safety is considered one of the key criteria for advanced highway trains and bogies. While a number of existing research studies have focused on its measurement and monitoring, this study proposes a new and effective train running a safety prediction framework. The wheel derail coefficient, wheel rate of load reduction, and wheel lateral pressure are considered the decision variables for the safety framework. Data for actual measured rail conditions and vibration-based signals are used as the input data. However, advanced trains and bogies are influenced more by their inertial structures and mechanisms than by railway conditions and external environments. In order to reflect their inertial influences, past data of output variables are used as recurrent data. The proposed framework shares advantages of a general deep neural network and a recurrent neural network. To prove the effectiveness of the proposed hybrid deep-learning framework, numerical analyses using an actual measured train-railway model and transit simulation are conducted and compared with the existing deep learning architectures.

Improving the track friendliness of a railway vehicle can make a significant contribution to improving the overall cost effectiveness of the rail industry. Rail surface damage in curves can be reduced by using vehicles with a lower Primary Yaw Stiffness (PYS); however, a lower PYS can reduce high-speed stability and have a negative impact on ride comfort. Previous studies have shown that this trade-off between track friendliness and passenger comfort can be successfully combated by using an inerter in the primary suspension; however, these previous studies used simplified vehicle models, contact models, and track inputs. Considering a realistic four-axle passenger vehicle model, this paper investigates the extent to which the vehicle's PYS can be reduced with inertance-integrated primary lateral suspensions without increasing Root Mean Square (RMS) lateral accelerations when running over a 5km example track. The vehicle model, with inertance-integrated primary lateral suspensions, has been created in VAMPIRE, and the vehicle dynamics are captured over a range of vehicle velocities and wheel-rail equivalent conicities. Based on systematic optimisations using network-synthesis theory, several beneficial inertance-integrated configurations are identified. It is found that with such beneficial configurations, the PYS can be reduced by up to 47% compared to a base case vehicle, without increasing lateral RMS accelerations. This could result in a potential Network Rail Variable Usage Charge saving of 26%. With the beneficial inertance-integrated suspensions, further simulations are carried out to investigate the vehicle's performance in curve transitions and when subject to one-off peak lateral track irregularities.

SARIOGLU, BURHAN/0000-0003-2245-791X WOS: 000477809600044 In this study, the mechanical properties of the air spring used in secondary suspension systems in railway vehicles have been experimentally determined. Firstly, rubber recipes with different components were determined for the production of rubber material, the main raw material of the air spring. Afterward, the mechanical properties of the elastomer material to be used in the manufacture of the air spring were determined by uniaxial tensile tests and RPA (rubber process analyzer) tests were applied to the samples obtained from different types of rubber compound. The machines used for the production of air spring and the test machines used for determining the mechanical properties of the air springs were specially produced and commissioned within the scope of the study. Blasting, airtightness, lifting-expansion, vertical spring coefficient, horizontal spring coefficient and lifetime tests were carried out by using these test machines. Ministry of Science, Industry and Technology of the Republic of Turkey [00853.STZ.2011-1] The authors express their sincere thanks to the Ministry of Science, Industry and Technology of the Republic of Turkey for supporting this research as the San-Tez program under contract number of 00853.STZ.2011-1. This paper is produced from MSc thesis of the first author.

A generalized railway vehicle model is built to study the coupled vibrations between a flexible car body (CB) and the equipment suspended beneath it by taking the complex suspension characteristics of the equipment into consideration. Associated theories for the determination of the suspension parameters for CB suspended equipment are summarized systematically, including the vibration isolation methods and the dynamic vibration absorber (DVA) theories for both undamped and damped cases. The equipment is then grouped into four categories by weight, location, and the excitation that it is subjected to. A general principle for the determination of the suspension parameters is proposed for better vibration isolation effects concerning bogie hunting, the elastic modes of the CB and its excitations. Analysis based on DVA theory shows that 1) siting equipment heavier than 2 t near the CB center can reduce the structural vibrations of the CB considerably, 2) siting medium-weight equipment near one end of the CB is good for absorbing the vibrations resulting from bogie hunting, and 3) a rigid connection is suggested for light equipment. Furthermore, on-track field tests of a high speed train confirmed that the heavy equipment vibrated violently upon absorbing some of the CB vibration energy resulting from bogie hunting. However, solid proof of the vertical bending of the CB was not obtained yet because it was sufficiently damped and is not the first natural mode of a modern aluminum-alloy CB. Further research on the lateral flexibility of the CB and its coupled vibrations with the heavy equipment mounted near its center are in need.

The regenerative braking of railway vehicles is widely used in DC railway systems all over the world. This mode of operation provides an opportunity to reuse part of the energy consumed by vehicles, and makes the railway system more energy efficient. During regenerative braking, not only energy management is an issue, but also Electromagnetic Compatibility EMC issues, such as interference of generated current harmonics with a railway signaling system. In this paper, the selective harmonic elimination modulation technique (SHE-PWM) was introduced to the traction drive with a three-level inverter to reduce specific catenary current harmonics generated during regenerative braking. The simulation model of a traction drive appropriate for harmonics analysis was proposed and verified by the measurements in the low-power laboratory drive system. The model was re-scaled to the 3 kV DC system for further study. The model of an induction motor with electromotive force and the method of its calculation was proposed. Furthermore, an analysis of the braking chopper operation was carried out. The asymmetric control of braking chopper was proposed to reduce the current harmonics below limits during chopper operation.

The paper herein analyzes the ride comfort at the vertical vibrations of the railway vehicle, evaluated by two methods—mean comfort method and Sperling’s method. The two methods have in common that the estimation of the comfort sensation is conducted with the comfort indices, namely ride comfort index NMVZ and ride comfort index Wz. The values of these indices are derived from numerical simulations. The advantage of using the results of the numerical simulations versus using experimental results, on which most previous research is based, resides in the fact that the ride comfort indices can be examined while taking into account the influence of velocity and certain parameters altering the behavior of vertical vibrations of the carbody, i.e., carbody flexibility and the suspension damping. The numerical simulation applications have been developed based on a theoretical model of the vehicle that considers important factors affecting the behavior of vertical vibrations of the carbody, by means of a ‘flexible carbody’ type model and an original model of the secondary suspension. The results presented mainly show that the two assessment methods lead to significantly different outcomes, in terms of ride comfort, under identical running conditions of the vehicle.

20th World Congress of the International-Federation-of-Automatic-Control (IFAC) -- JUL 09-14, 2017 -- Toulouse, FRANCE, WOS: 000423964800104, In this work, the mathemtical model of a railway passenger car with conventional and radial-elastic wheels is analyzed. Stochastic excitations are applied to the wheelsets. The local elasticity between the wheel and the rail is modelled by a linearized stiffness behaviour due to geometrical effects to simplify the controller design procedure for H-2 analysis. An optimization of the vertical dynamics is performed by reducing the the H-2 norms of the dynamic wheel forces while keeping the RMS gain of carbody accelerations at a constant level. It is seen that the controller performs well on the low frequency range where the ride comfort is more pronounced and partially on the high frequency range to suppress the environmental ground vibrations and structure-borne noise, Int Federat Automat Control, Continental Automot, Occitanie Reg, Toulouse Metropole, CNES, Univ Toulouse III, Paul Sabatier, Inria, CNRS, OPTITRACK, MDPI, ISAE Supaero, iCODE, EECI, Int Journal Automat & Comp, IEEE CAA Journal Automatica Sinica, Moveo

This study proposes a newly developed structure for a frequency-dependent orifice for an air spring of a passenger train vehicle. This frequency-dependent orifice reduced both the rolling motion and the vertical vibration at high frequency. This paper also presents the numerical simulation results. Optimal settings of the springs and dampers of the bogie are essential for reducing the uncomfortable carbody motion while the train is running. The air springs provide insulation and damping through air compressibility in the bellows and pressure loss of the airflow passing through an orifice installed between the air spring and the auxiliary reservoir. The frequency characteristics of a standard air spring show a peak at a frequency of ~1 Hz of the rolling motion of the carbody. A smaller orifice seems to be one of the solutions to change this characteristic. However, this method worsens the damping property at high frequency. To solve this problem, a frequency-dependent orifice with active vibration control technology has been proposed. This orifice improves the vertical vibration at low frequencies and the rolling motion of the carbody; however, it does not improve the properties at high frequencies. The results of our previous research left issues such as the need to improve the high-frequency response in a future study. The results of this study show that our newly developed frequency-dependent orifice effectively reduces the vertical vibration at high frequency with no external power supply. We are planning further simulations including realistic disturbance and a running test using a prototype of the frequency-dependent orifice.

There is an increasing desire in the railway industry to improve the longevity of wheels and rails without reducing performance in other ways (e.g. worsening passenger comfort). One way of reducing track and wheel wear is to reduce the primary yaw stiffness, significantly diminishing the costs associated with maintenance and emergency repairs, resulting however in reduced passenger comfort and high-speed stability. This paper, using a two-axle railway vehicle case study, demonstrates the potential of using passive, inerter-based suspensions to concurrently improve ride comfort and reduce track wear. The industrial parameter T Gamma is used to quantify the frictional energy lost at the contact patch under curving conditions, and the lateral RMS carbody acceleration is used to quantify passenger comfort under straight running conditions, with lateral track disturbances taken from real track data. Optimisation results conclude that, with the default yaw stiffness value, compared with the default spring- damper configuration in the primary lateral suspension, employing beneficial inerter-based configurations can improve passenger comfort by up to 43%. If the yaw stiffness is reduced such that the track wear is improved, similar improvements in passenger comfort can still be achieved with lateral inerter-based suspensions; for example, an improvement of 33% can still be achieved with a 50% reduction in yaw stiffness. Furthermore, when an inerter-based lateral suspension is used together with a Hall-Bush longitudinal suspension, the passenger comfort rises to 40%, which relates to a 25% improvement when compared with a non-inerter lateral plus Hall-Bush longitudinal setup.

The theoretical research on means to reduce the vertical vibrations and improve the ride comfort of the railway vehicle relies on a mechanical model obtained from the simplified representation of the vehicle, while considering the important factors and elements affecting the vibration behaviour of the carbody. One of these elements is the anti-yaw damper, mounted longitudinally, between the bogie and the vehicle carbody. The anti-yaw damper reduces the lateral vibrations and inhibits the yaw motion of the vehicle, a reason for which this element is not usually introduced in the vehicle model when studying the vertical vibrations. Nevertheless, due to the position of the clamping points of the anti-yaw damper onto the carbody and the bogie, the damping force is generated not only in the yawing direction but also in the vertical and longitudinal directions. These forces act upon the vehicle carbody, impacting its vertical vibration behaviour. The paper analyzes the effect of the anti-winding damper on the vertical vibrations of the railway vehicle carbody and the ride comfort, based on the results derived from the numerical simulations. They highlight the influence of the damping, stiffness and the damper mounting angle on the power spectral density of the carbody vertical acceleration and the ride comfort index.

The equipment mounted on the carbody chassis of the railway vehicles is a critical component of the vehicle in terms of ride comfort. The reason for that is their large mass, able to visibly influence the vibrations mode of the carbody. The paper examines the influence of the equipment upon the mode of vertical vibrations of the carbody in the high-speed vehicles, reached on the basis of the frequency response functions of the acceleration in three carbody reference points - at the centre and above the bogies. These functions are derived from the numerical simulations developed on a rigid-flexible coupled model, with seven degrees of freedom. As a rule, the results herein prove the influence of the equipment mounting mode (rigid or elastic), along with the speed regime, upon the level of vibrations in the carbody reference points, at the resonance frequency of the symmetrical bending mode. Similarly, it is also demonstrated how the equipment mass and the damping degree of the suspension system affect the level of the vibrations in the carbody.

The paper focuses on a nonlinear model to represent the mechanical behaviour of a mix coil spring - rubber used in the secondary suspension of passenger rail vehicles. The principle of the model relies on overlapping of the forces corresponding to three components - the elastic component, the viscous component and the dry friction component. The model has two sources on non-linearity, in the elastic force and the friction force, respectively. The main attributes of the model are made visible by its response to an imposed displacement-type harmonic excitation. The results thus obtained from the applications of numerical simulation show a series of basic properties of the model, namely the dependence on amplitude and the excitation frequency of the model response, as well as of its stiffness and damping.

This paper describes a simplified practical approach to the impact damage assessment of flying ballast or debris in composite materials, which could potentially be used for passenger rail vehicles. With the development of high-speed lines in order to guarantee the safety of primarily the driver and passengers, the vehicle body shell must be strong enough to resist the penetration of these types of objects into the vehicle. Currently the EN12663 standard has insufficient information on missile impact requirements for car bodies. Using the requirements of British Railway Group Standard GM/RT2100, GFRP composite material was analyzed in both static and dynamic events. Impact events at high velocities (V>50 m/s) lead to difficulties in testing due to the requirements for specific and expensive equipment and safety issues in the test application process. The simpler assessment and testing method described in this paper aims to provide a more cost effective, less time consuming, easily applicable method, with accurate results compared to existing methods. Previous research found that high-velocity impact behavior of composite materials can be mimicked by quasi-static punch tests (QSP). In this study, QSP tests were performed with E-glass/polyester composite laminates and FE simulations were carried out to match the experiments. The resulting numerical material and modelling data was used to simulate high velocity impact cases to assess the response of the material and to determine the connection between static and dynamic cases.

This abstract describes the experience of a railway vehicle dynamics simulation using Universal Mechanism software. The software system Universal Mechanism (UM) was created for computer simulation of kinematic and dynamic processes of different mechanical systems, it is especially efficient for railway rolling stock simulations tasks. UM software includes different models (simplified and 3D models) of railway rolling stock and different software tools for simulation of railway vehicle dynamics. Researchers at the VGTU Railway Transport Department constantly and successfully use the UM for the educational and research purposes. For example the UM software was used for the simulation of a railway accident on the track between stations Gaižiūnai and Skaruliai. In this case six wagons derailed in very complicated circumstances. To determine the actual cause of the accident, the computer two stage model of the accident was created: at the first stage the simplified model was created and at the second stage the 3D simulation of the train dynamics was made. After creating the dynamic model of the train and analyzing the results, it was determined that the UM simulates only a single braking process of the train. That does not reliably recreate the conditions of the train and the train longitudinal conditions in the simulation process are absolutely unpredictable. That distorts the results of the simulation. Working in collaboration with the manufacturer of the UM − Laboratory of Computational Mechanics of Bryansk State Technical University, the UM software has been supplemented with the new feature which creates multibraking conditions of the train. The new version of the UM was made to re-model various train braking processes (service braking, releasing and emergency braking) with full restoration of black box tape recordings. This suggests that the results of modeling are absolutely true and can accurately determine the cause of the derailment. The simulation experience not only enhances the UM software abilities, but also created models allow to simulate lon-gitudinal dynamic processes of all train running regimes.

The paper herein focuses on the dynamic response of a two-bogie vehicle to the excitations derived from the track vertical irregularities. The symmetrical and antisymmetrical modes due from the bounce and pitch motions of the axles’ planes in the two bogies are being considered. The analysis of the dynamic response in the vehicle relies on the response functions in three reference points of the carbody, composed by means of these response functions to the symmetrical and antisymmetrical excitation modes. Similarly, the dynamic response of the vehicle to the track stochastic irregularities is examined and expressed as a power spectral density of the carbody vertical acceleration and the root mean square of the acceleration and the index of the partial comfort to the vertical vibrations is calculated. The paper is structured into two parts. The Part I includes all the theoretical elements required for the analysis of the dynamic response in the vehicle, while Part II introduces the results of the numerical analysis.

Starting from the knowledge of flush air data-sensing systems developed in the aerospace field, a system able to evaluate the crosswind velocity (absolute and angle) from pressure measurements performed on a train’s surface has been studied and developed. The crosswind evaluation algorithm is based on a neural network and is created and tested using pressure measurements carried out during wind tunnel tests on a scale-model of a railway vehicle. The number and positions of pressure taps on the surface of the train’s leading car are optimized, in terms of the sensitivity and robustness of the measurement system. The system is calibrated and validated using steady and quasi-steady wind tunnel tests on a scale model of a train. The designed neural network gives a maximum error of about 1 m/s for the modulus and 1° for the angle of the relative velocity.

This paper evaluates the level of the vertical vibrations in a railway vehicle carbody generated by the track irregularities and examines the position of the critical point from the comfort perspective. The issue is reviewed on the basis of both a „rigid carbody” model and a „flexible carbody” model, which considers the first two carbody bending modes. The model errors are calculated as a function of the speed behaviour, and the results prove that the comfort performance of a railway vehicle evaluated on the „rigid carbody” model basis are overestimated compared to the ones derived from the implementation of the „flexible carbody” model, mainly at the centre of the carbody. Similarly, a correct estimation of the critical point position in the level of vibrations requires the modelling of the structural vibrations of the vehicle carbody.

Against the deficiencies of traditional time domain and frequency domain analysis in detecting wheel-rail (W-R) system hidden risks which wheel flats generate, the time-frequency characteristics of W-R shock caused by wheel flat are analyzed and the vehicle-rail dynamic model with wheel flat is investigated. The 10 degrees of freedom (DOF) vehicle model is built up. 90-DOF rail model is constructed. The wheel flat excitation model is built up. The vehicle-track coupling dynamic model including wheel flat excitation is set up through nonlinear Hertzian contact theory. The vertical accelerations of axle box are calculated at different speeds and flat sizes based on the vehicle-track coupling dynamic model with wheel flat. Frequency slice wavelet transform (FSWT) is employed to analyze time-frequency characteristics of axle box accelerations to detect the W-R noncontact risks s which the traditional time domain or frequency domain method does not analyze. The results show that the small flat size and high running speed lead to high frequency W-R impact. Large flat size and high running speed result in momentary loss of W-R contact, and there exist security risks between wheel and rail. The conclusion that the phase of axle box accelerations is same to W-R forces lays a theoretical foundation of monitoring W-R contact safety from axle box acceleration instead of traditional W-R force detection.

A computational fluid dynamics (CFD) analysis of air distribution in a representative railway vehicle equipped with a heating, ventilation, air conditioning (HVAC) system is presented in this paper. Air distribution in the passenger’s compartment is a very important factor to regulate temperature and air velocity in order to achieve thermal comfort. A complete CFD model, including the car’s geometry in detail, the passengers, the luminaires, and other the important features related to the HVAC system (air supply inlets, exhaust outlets, convectors, etc.) are developed to investigate eight different typical scenarios for Northern Europe climate conditions. The results, analyzed and discussed in terms of temperature and velocity fields in different sections of the tram, and also in terms of volumetric parameters representative of the whole tram volume, show an adequate behavior from the passengers’ comfort point of view, especially for summer climate conditions.

The paper includes a short review of selected problems in railway vehicle-track system dynamics which are related to the running safety. Different criteria used in assessment of the running safety are presented according to the standards which are in force in Europe and other countries. Investigations of relevant dynamic phenomena, including the mechanism of railway vehicle derailment, and the resulting modifications of the running safety criteria are also discussed.

The DLR research project Next Generation Train deals with concepts, methods and technologies for a very high-speed train in double deck configuration and light-weight design. Due to these three key features crosswind stability is a particular subject of study. It is shown that conventional approaches here fall short of guaranteeing safety in high-wind occurrences according to the given homologation standards. Therefore this paper discusses the feasibility of different approaches to ensure crosswind stability by means of active control. Four different concepts are overviewed, the most promising one is then chosen und examined in detailed multibody simulations that are based on data from wind tunnel measurements of the Next Generation Train.

High speed railway vehicles features a specific lateral oscillation resulting from the coupled lateral displacement and yaw of the wheelset which leads to a sinusoid movement of the wheelset along the track, transferred to the entire vehicle. The amplitude of this oscillation is strongly dependant on vehicle's velocity. Over a certain value, namely the critical speed, the instability phenomenon so-called hunting occurs. To raise the vehicle's critical speed different designs of the suspension all leading to a much stiffer vehicle can be envisaged. Different simulations prove that a stiffer central suspension will decrease the passenger's comfort in terms of lateral accelerations of the carboy. The authors propose a semi-active magneto rheological suspension to improve the vehicle's comfort at high speeds. The suspension has as executive elements hybrid magneto rheological dampers operating under sequential control strategy type balance logic. Using an original mathematical model for the lateral dynamics of the vehicle the responses of the system with passive and semi-active suspensions are simulated. It is shown that the semi-active suspension can improve the vehicle performances.

A brake hardware-in-the-loop simulation system for a railway vehicle provides an effective platform for testing the braking performance under various dangerous braking conditions. However, in general, four-brake calipers are required to implement a mechanical brake system for one car. In this article, we implement a brake hardware-in-the-loop simulation system only with one brake caliper and three air tanks accounting for hysteresis and pneumatic cylinder dynamics, ultimately saving installation space and reducing financial budget costs. Since the brake caliper has a high nonlinearity, such as hysteresis resulting from friction and from the precompressed spring of the brake cylinder, we measured the hysteresis of the brake caliper clamping force for a mechanical brake system using loadcells, based on which a mathematical model was constructed for the hysteresis of the clamping force between the brake pad and the disk. Moreover, the pneumatic cylinder dynamics are identified and are implemented in three air tanks, together with hysteresis nonlinearity. The proposed brake hardware-in-the-loop simulation system is applied to the wheel-slide protection simulation of a railway vehicle with an initial speed of 80 km/h and demonstrated experimentally accounting for the hysteresis and brake cylinder dynamics.

The weld quality has a significant influence on the fatigue strength of welded joints and components. In the industrial field, there are different manufacturing conditions and as a consequence of this, the weld quality can vary considerably. Therefore, fatigue tests of different joint types were performed, analysing the influence of manufacturing conditions and of weld quality on the fatigue strength of welded components of railway vehicles. For these fatigue tests, typical welded joints with the significantly different notch effect were selected, i.e. butt weld specimens with relatively low notch effect and cruciform joints with relatively high notch effect. These specimens were made under typical industrial conditions by three different companies from the railway industry (Bombardier, Siemens, and ALSTOM). Thus, they represented the weld quality level of this industrial field. Prior to the fatigue testing of these specimens, the weld quality was checked in accordance with the criteria of the DIN EN 15085, which is based upon the general weld quality standard DIN EN ISO 5817. On the basis of the result of this weld quality inspection, most specimens have the quality level B relating to DIN EN ISO 5817. The fatigue tests under axial loading show a significantly higher fatigue strength level for the nominal approach in comparison with IIW Recommendations. However, the determined fatigue stress range of both joint types investigated is conservative, in comparison with the allowable fatigue strength of the actual guidelines or standards applied in the railway industry. For both joint types investigated the relevant notch stress range was determined based on the results for nominal fatigue strength. The fatigue strength differences between the notch stress range of the test results and the notch fatigue resistance of the IIW Recommendations are significantly less than the differences in the nominal strength comparison. The determined nominal fatigue strength values of the investigated welded joints correspond to the weld quality level B, as defined by DIN EN ISO 5817, and additionally, to the requirement of angular distortion = 0.75 x plate thickness and to the root face length

An essential step toward the development of intelligent and efficient technologies applied to complex systems is to provide self-diagnosing capability. For this to happen, sensors, data analysis, fault detection, and health assessment must be interconnected. This paper discusses on a predictive diagnostic strategy that can be used to monitor the aging of railway power converter units.

In this paper, the influence on corrugation of the most significant track parameters has been examined. After this parametric study, the optimization of the track parameters to minimize the undulatory wear growth has been achieved. Finally, the influence of the dispersion of the track and contact parameters on corrugation growth has been studied. A method has been developed to obtain an optimal solution of the track parameters which minimizes corrugation growth, thus ensuring that this solution remains optimum despite dispersion of track parameters and wheel-rail contact uncertainties. This work is based on the computer application RACING (RAil Corrugation INitiation and Growth) which has been developed by the authors to predict rail corrugation features. CEDEX, through contract PT2006-024-19CCPM. Department of Education, Universities and Research of the Basque Government.