Abstract: Impact forces develop at the wheel/rail interface due to the presence of defects in the running surface of the wheel and/or the railhead. This paper reports on wheel impacts, caused by permanently dipped rail joints, that are characterised by high-frequency impact forces generated by high amplifications of the static load that occur for a very short duration (P1 forces), followed by relatively low frequency, lower amplitude forces (P2 forces) that occur for a longer duration. These impact forces are affected by the design of components adjacent to the wheel and rail, namely the bogie’s primary suspension and rail seat pads; the influences of stiffness and damping characteristics of these components are investigated. A modified three-dimensional simulation model of the dynamics of the wagon/track system that includes defects in the track is created and is used to obtain the time series of the impact force. This is converted into impact force factors that are compared with a set of field-measured data repor...

Abstract: Aerodynamic noise becomes significant for high-speed trains and its prediction in an industrial context is difficult to achieve. The aerodynamic and aeroacoustic behaviour of the flow past a simplified high-speed train bogie at scale 1:10 is studied using a two-stage hybrid method comprising computational fluid dynamics and acoustic analogy. The near-field unsteady flow is obtained by solving the Navier-Stokes equations numerically with the delayed detached-eddy model and the results are used to predict the far-field noise through the Ffowcs Williams-Hawkings method. The sound radiated from the same scaled bogie model is measured in an anechoic open-jet wind tunnel. The aeroacoustic characteristics of tandem wheelsets are also investigated for comparison. It is found that the unsteady flow past the bogie is characterized by coherently alternating vortex shedding from the axles and more randomly distributed vortices of various scales and orientations from the wheels and frame. The vortices formed behind the upstream geometries are convected downstream and impinge on the downstream bodies, generating a highly turbulent wake behind the bogie. The noise predictions correspond fairly well with the experimental measurements for the dominant frequency of tonal noise and the shape of spectra. Vortex shedding from the axles generates the tonal noise with the dominant peak corresponding to the vortex shedding frequency. The directivity exhibits a dipole shape for the noise radiated from the bogie. Compared to the wheelsets of the bogie, the noise contribution from the bogie frame is relatively weaker.

Abstract: The effects of bogie primary and secondary suspension stiffness and damping components on the dynamics behavior of a high speed train are scrutinized based on the multiplicative dimensional reduction method (M-DRM). A one-car railway vehicle model is chosen for the analysis at two levels of the bogie suspension system: symmetric and asymmetric configurations. Several operational scenarios including straight and circular curved tracks are considered, and measurement data are used as the track irregularities in different directions. Ride comfort, safety, and wear objective functions are specified to evaluate the vehicle’s dynamics performance on the prescribed operational scenarios. In order to have an appropriate cut center for the sensitivity analysis, the genetic algorithm optimization routine is employed to optimize the primary and secondary suspension components in terms of wear and comfort, respectively. The global sensitivity indices are introduced and the Gaussian quadrature integrals are employed to evaluate the simplified sensitivity indices correlated to the objective functions. In each scenario, the most influential suspension components on bogie dynamics are recognized and a thorough analysis of the results is given. The outcomes of the current research provide informative data that can be beneficial in design and optimization of passive and active suspension components for high speed train bogies.

Abstract: The axle-box acceleration is regularly measured by the track inspection car in Japan. We examined the technique for managing the rail corrugation by making use of the axle-box acceleration measured by the inspection car. Concretely, we analyzed the relation between the axle-box acceleration data and the rail surface roughness data measured on the ground. In that case, the influence of the difference of the measurement axle of the bogie and the difference of measuring speed of the axle-box acceleration on the detection accuracy of the rail surface roughness was examined. As a result, we have confirmed that the rail corrugation is able to be managed efficiently by using the axle-box acceleration measured by the leading axle of the bogie in case where the track inspection car runs with a usual speed.

Abstract: Rutting caused by heavy machinery during logging operations can lead to loss of trafficability which is a considerable problem in designated skid trail systems. Wide base tires and bogie tracks are common accepted technical options to minimize rut formation. In this work the suitability of 940 mm super wide base tires on trafficability preservation was tested in comparison to 710 mm wide base tires and common used ECO-TRACK™ bogie tracks. An experiment with repeated passes by a heavy forest machine (forwarder) was conducted. Digital elevation models (DEM) of the ruts were created using photogrammetry to assess rut morphology parameters: rut depth, material displacement and erosion relevant depression storage capacity. Photogrammetry was discovered to be a time and cost efficient method to provide highly resolved 3D-data with high precision. Super wide base tires distinctly reduced rut formation compared to 710 mm tires and bogie tracks by more than 50% and 40%, respectively. Displacement of soil material led to the formation of prominent bulges that can be prone to erosion. 710 mm tires and bogie tracks caused the most voluminous bulges due to their strong rut formation. The investigated tire equipment differently affected the surface depression storage of water in the skid trails due to their different lug morphology. Ruts of bogie tracks could retain significantly more surface water than ruts produced by tires. Nonetheless, the absolute depression storage in all cases is rather low, implying that erosion would occur in case of heavy precipitation.

Abstract: The high-speed train has achieved great progress in the last decades. It is one of the most important modes of transportation between cities. With the rapid development of the high-speed train, its safety issue is paid much more attention than ever before. To improve the stability of the vehicle with high speed, extra dampers (i.e. anti-hunting damper) are used in the traditional bogies with passive suspension system. However, the curving performance of the vehicle is undermined due to the extra lateral force generated by the dampers. The active suspension systems proposed in the last decades attempt to solve the vehicle steering issue. However, the active suspension systems need extra actuators driven by electrical power or hydraulic power. There are some implementation and even safety issues which are not easy to be overcome. In this paper, an innovative semi-active controlled lateral suspension system for railway vehicles is proposed. Four magnetorheological fluid dampers are fixed to the prima...

Abstract: In this paper, the lateral mathematical model of a railway wheel-set with two degrees of freedom has been built. To study the effect of yaw damper on the stability of high-speed wheel-set, the constrain between the wheel-set and the bogie is assumed as rigid. In this lateral model, only the nonlinear wheel/rail contact relationship has been taken into consideration in the lateral direction, due to both the nonlinear relationship between lateral displacement and contact angle of the wheel and the rail, and the nonlinear relationship between lateral displacement and the equivalent radius of the wheel at the contact point. And the nonlinear parameters are attained by using polynomial interpolation. By using Center Manifold Theorem, the method of Normal Form and Poincare method, the model is reduced to a planar dynamical system, and the symbolic expression of the first-order fine focus is given, which can be used to determine which kind of bifurcation will occur at the critical speed. The simulation is established by using the parameters of the wheel-set of Chinese high-speed railway vehicle CRH3, and the result is consistent with the determination of the first-order fine focus. At last, the influence of different parameters on the stability of CRH3 wheel-set is investigated.

Abstract: To improve safety and maximum admissible speed on different operational scenarios, multiobjective optimisation of bogie suspension components of a one-car railway vehicle model is considered. Track shift force, running stability, and risk of derailment are selected as safety objective functions. To attenuate the number of design parameters for optimisation and improve the computational efficiency, a global sensitivity analysis is accomplished using the multiplicative dimensional reduction method (M-DRM). A multistep optimisation routine based on genetic algorithm and MATLAB/SIMPACK co-simulation is executed at three levels.The bogie conventional secondary and primary suspension components are chosen as the design parameters in the first two steps, respectively. In the last step semi-active suspension is in focus. The input electrical current to magnetorheological yaw dampers is optimised to guarantee an appropriate safety level. Semi-active controllers are also applied and the respective effects on bogie dynamics are explored. The safety Pareto optimised results are compared with those associated with in-service values. The global sensitivity analysis and multistep approach significantly reduced the number of design parameters and improved the computational efficiency of the optimisation. Furthermore, using the optimised values of design parameters give the possibility to run the vehicle up to 13% faster on curves while a satisfactory safety level is guaranteed. The results obtained can be used in Pareto optimisation and active bogie suspension design problems.

Abstract: The utility model provides a single track train power truck of a formula is striden to diaxon relates to city bogie technical field for the monorail transit haulage vehicle, this bogie of includes the framework, walks the road wheel device, leading wheel device, stabilising wheel device, walk capable auxiliary wheel device, secondary suspension system, draw gear, basic brake unit, drive arrangement, walk road wheel tyre pressure monitoring device and collecting electrode, this bogie is whole strides a formula haulage vehicle 0 structure for the diaxon The utility model discloses the traction motor of bogie adopts the erection of framing mode, can reduce operating noise, improves the reliability, automobile body guest room space is not invaded to the bogie, and face whole bogie tops that lie in in automobile body ground can be realized spacious guest room and arranged the design

Abstract: Numerical analysis of the superconducting magnetically levitated bogie (JR Maglev) has been studied. In this system, electrodynamic suspension with the null-flux configuration is applied to keep the levitation and guidance position of the train without gap control. However, the damping factor of the system is little. The active damper coil is introduced to increase the damping factor. It has a large effect on reducing the vertical vibration. However, when the vertical vibration and pitching motion occur simultaneously, it does not control the vibration perfectly. The control method of the active damper coil is studied. The improved switching function (combined switching) that has an effect on the multidirectional vibration is modeled. Running simulation when the bogie passes the guideway displacement has been undertaken. The active damper that is controlled by the combined switching decreases the multidirectional vibration.

Abstract: An intermodal transport is nowadays an inseperable part of a transport system. Designs of longer wagons are the result of efforts to achieve universality, transport capacity increase, reducing of noise and maintenance needs. In this paper are presented results of selected parametres of a long goods wagon driving on a test track. The long goods wagon and test rings models have been created by using the ADAMS/Rail software. The analysed wagon has been equipped by the Y25 bogie. Simulations of the long goods wagon running have been performed on the model of railway test rings - VUŽ Velim, Cerhenice. For the dynamic analysis of the long goods wagon have been selected two sections of the railway test rings. For the ride properties wagon assessemnt have been selected output signals of vertical forces Q, guiding forces Y and the Y/Q ratio. There have been detected, values of assessed parametes have not been exceeded the limited values and therefore wagon runnings have been safety.

Abstract: The article deals with the results of the simulation analysis of a railway wagon bogie model. We analysed four freight wagon bogie variants for its dynamics properties research. The bogie models correspond in general to the Y25 bogie concept. The models were created in SIMPACK software enhanced by the RAIL module. From the research results depicted in the graphs we found out, that the newly designed bogie variant gives the best results when compared to the other analysed versions. The newly designed model consists of a standard Y25 bogie frame with two Lenoire friction dampers. This bogie is equipped with longitudinal linkages on both sides. These linkages are completed with a radial torsion binding, torsion rod, between side bogie parts. The contact of railway wheels and rails generates active forces affecting the surface contact, affecting the size of the normal and tangential stress, wear surfaces of the wheel/rail, or directly the size of the derailment.

Abstract: When a train runs at high speeds, the external exciting frequencies approach the natural frequencies of bogie critical components, thereby inducing strong elastic vibrations. The present international reliability test evaluation standard and design criteria of bogie frames are all based on the quasi-static deformation hypothesis. Structural fatigue damage generated by structural elastic vibrations has not yet been included. In this paper, theoretical research and experimental validation are done on elastic dynamic load spectra on bogie frame of high-speed train. The construction of the load series that correspond to elastic dynamic deformation modes is studied. The simplified form of the load series is obtained. A theory of simplified dynamic load–time histories is then deduced. Measured data from the Beijing–Shanghai Dedicated Passenger Line are introduced to derive the simplified dynamic load–time histories. The simplified dynamic discrete load spectra of bogie frame are established. Based on the damage consistency criterion and a genetic algorithm, damage consistency calibration of the simplified dynamic load spectra is finally performed. The computed result proves that the simplified load series is reasonable. The calibrated damage that corresponds to the elastic dynamic discrete load spectra can cover the actual damage at the operating conditions. The calibrated damage satisfies the safety requirement of damage consistency criterion for bogie frame. This research is helpful for investigating the standardized load spectra of bogie frame of high-speed train.

Abstract: The article presents a summary of several years (2009-2015) of studies on the application of mobile satellite Global Navigation Satellite Systems (GNSS) measurements in the field of designing and operation of railways. These studies have been conducted by an interdisciplinary research team from the Gdansk University of Technology and the Gdynia Maritime University. Mobile satellite GNSS measurements are taken during a ride (through the railroad) by the measuring train consist of motor car with a trailed double axles platform bogies on which the GNSS receivers were installed. The authors described the adopted methodology of the carried out measurements of the rail and tram tracks. The problem of an accuracy of satellite positioning measurements has been discussed. The authors proposed a method that makes it possible to assess quantitatively the accuracy of the research implemented over years. New concepts were introduced, such as: GNSS positioning networking service availability, reliability and continuity based on the theory of reliability. Using a developed mathematical model they recounted the results of four archival measurement campaigns of years: 2009-2015. The studies have shown that the number of used satellite systems as well as support for GNSS measurements with the inertial system are important from the point of view of the accuracy of the results.

Abstract: The influence of wheel and rail profile shape features on the initiation of rolling contact fatigue (RCF) cracks is evaluated based on the results of multi-body vehicle dynamics simulations. The damage index and surface fatigue index are used as two damage parameters to assess the influence of the different features. The damage parameters showed good agreement to one another and to in-field observations. The wheel and rail profile shape features showed a correlation to the predicted RCF damage. The RCF damage proved to be most sensitive to the position of hollow wear and thus bogie tracking. RCF initiation and crack growth can be reduced by eliminating unwanted shape features through maintenance and design and by improving bogie tracking.

Abstract: The superconducting magnetically levitated train (JR Maglev) has been developed. Electrodynamic suspension realizes stable levitation and guidance without gap control. As the damping against the bogie vibration is small, the damper coil system has been proposed to control vibration of the bogie. Superconducting (SC) coil quenching is one of the most serious problems. Although the effect of the damper coils in the case of SC coil quenching has been confirmed, influence of the position of the quenched coils on the bogie motion is not shown. In this paper, the dependence of the quenched coil position on the bogie is studied. When the end coil of the bogie quenches, the levitation force and guidance force reach twice and five times compared with the ordinary force. In the case of inside coil quenching, the exceptional force is supported by each side of the SC coils. Thus, its influence becomes small. Even in the case of end coil quenching, damper coils control the large vibration.

Abstract: The invention discloses a single axle bogie transmission of a straddle-type single rail vehicle. The transmission is arranged on a bogie frame and used for realizing that walking wheels are driven to walk through the torque of a motor. The transmission comprises the motor, a brake disc, a walking wheel assembly and a reducer. The motor and the brake disc are transversely arranged on the fixed end of an axle, and the walking wheel assembly and the wheel reducer are transversely arranged on the cantilever end of the axle; a walking wheel support shaft is unidirectionally fixed by adopting double fulcrums, one end of the support shaft is fixed on the bogie frame, the other end of the support shaft is suspended, the fixed end of the support shaft is supported by a self-aligning roller bearing, and the cantilever end of the support shaft is supported by a group of tapered roller bearings installed in an axle box in the reverse direction. Longitudinal symmetric planes of the walking wheels are coincided with longitudinal symmetric planes of track beams. The single axle bogie transmission of the straddle-type single rail vehicle has the technical beneficial effects that the bogie is compact in structure, tires are disassembled and assembled easily, and the curve passing performance of the cantilever beam straddle-type single rail vehicle is met.

Abstract: The rocker-bogie suspension system has robust capabilities to deal with uneven terrain because of its distributing of the payload over its six wheels uniformly, while there is one major shortcoming to high-speed traversal over the planar terrain. This paper proposes a new dynamic rocker-bogie suspension system with two modes of operation: it can expand the span of the rocker-bogie support polygon to increase travel rate when the terrain is planar; and it can switch to its original configuration to move by low speed when it is faced with rough terrain. The analysis on dynamic stability margin and kinematical simulation on the two operating modes of rocker-bogie are employed to analyze and verify the rationality and effectiveness of the modification in the structure.

Abstract: The maintenance of bogie components, a critical aspect of railway maintenance, is difficult due to the confined underframe space. This makes it difficult to install traditional monitoring equipment, resulting in a labour-intensive process. Thus, a lot of time has to be expended to conduct these tests, which makes the process both tedious and expensive. Moreover, this approach is somewhat inadequate, since the tests can only be conducted at the depot and thus only when the trains are out of service. The authors have developed and deployed a non-intrusive solution based on a small wireless sensor network that can be easily installed on the different parts of the bogie and along the whole train. The authors have worked out a technique to discriminate between the various sources of vibration and can thus monitor the state of several components using only a few sensors. In this paper, the authors present a case study on how to maintain an axle-box and a wheel-set by attaching a single intelligent sensor to the bogie frame or the bearing cover and using the empirical mode decomposition technique to analyse the generated data. In light of the promising results obtained in this study, the authors suggest that the proposed approach can lead to a value-added predictive maintenance strategy as long as the test conditions are kept under control. However, the authors do highlight that the generalization of the approach relies on the flexibility of the system to adapt to new environments and operational scenarios.

Abstract: The paper deals with simulation analysis of a rail vehicle with a tilting bogie. The goal is to determine the wheel force in the rail-wheel contact and subsequently determine the safety against derailment. The rail vehicle model was designed in CAD program CATIA and imported to program SIMPACK with the RAIL module extension afterwards. Eight variants of different velocity, vehicle occupancy and setting of the tilting mechanism were analysed. The vehicle model was run along a track composed of straight sections and four succesive curves. Diagrams of the examined quantities icluding the lateral flanging force, vertical wheel load and the safety against derailment for the eight different variants make the result of the simulation analysis. Arising from the analysis, the biggest differences of results can be seen between the two variants of the highest speed but with different occupancy.

Abstract: The maglev bogie is the key subsystem for maglev train security. To ensure life and property security, it is essential to evaluate its risk level before its operation. In this paper, a combinational method of analytic hierarchy process and fuzzy comprehensive evaluation is proposed to assess hazards in a complex maglev bogie system associated with multiple subsystems’ failures. The very comprehensive identification of risk sources has been done by analyzing the structure of maglev bogie. Furthermore, based on the fuzzy theory, linguistic evaluation set is classified according to risk tolerance. The score of each risk factor is obtained by weighted sum of the result of fuzzy comprehensive evaluation. Our results show that the degree of maglev bogie’s risk is within the range of acceptability. The merits of this work facilitate finding the weak links and determining the maintenance of maglev bogie system.

Abstract: Modern tram designs use different conceptions of how to implement the low-floor functionality. The key construction part is the bogie running gear which has to accommodate the lower part of the tram body. To adjust the low-floor level, many low-floor tram bogies have different types of guidance of independently rotating wheels with no central axle between the two wheels. Lack of self-steering mechanism in the form of central axle coupling or an external guiding device creates several inherent problems, such as insufficient guiding and excessive wear. Another important context is the safety against derailment when the vehicle negotiates a curved track. In this study the dynamic behaviour of non-powered bogies with different types of guidance of independently rotating wheels are presented using computer simulation models. The simulation results of the Y/Q index are compared for the two track configurations (curved and tangent sections) and four different kinds of bogie running gear.

Abstract: A robust controller is designed for active steering of a high speed train bogie with solid axle wheel sets to reduce track irregularity effects on the vehicle’s dynamics and improve stability and curving performance. A half-car railway vehicle model with seven degrees of freedom equipped with practical accelerometers and angular velocity sensors is considered for the H∞ control design. The controller is robust against the wheel/rail contact parameter variations. Field measurement data are used as the track irregularities in simulations. The control force is applied to the vehicle model via ball-screw electromechanical actuators. To compensate the actuator dynamics, the time delay is identified online and is used in a second order polynomial extrapolation carried out to predict and modify the control command to the actuator. The performance of the proposed controller and actuator dynamics compensation technique are examined on a one-car railway vehicle model with realistic structural parameters and nonlinear wheel and rail profiles. The results showed that for the case of nonlinear wheel and rail profiles significant improvements in the active control performance can be achieved using the proposed compensation technique.