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To explore the impact of wheel-rail excitation on the dynamic performance of axle box bearings, a dynamic model of the high-speed train including axle box bearings is developed. Subsequently, the dynamic response characteristics of the axle box bearing are examined. The investigation focuses on the acceleration characteristics of bearing vibration under excitation of track irregularities and wheel flats. In addition, experiments on both normal and faulty bearings are conducted separately, and the correctness of the model and some conclusions are verified. According to the research, track irregularity is unfavorable for bearing fault detection based on resonance demodulation. Under the same speed conditions, the acceleration peak of bearing is inversely proportional to the length of the wheel flat and directly proportional to its depth. The paper will contribute to a deeper understanding of the dynamic performance of axle box bearings. [ABSTRACT FROM AUTHOR]

This paper introduces a novel nothing-on-road (NOR) bridge weigh-in-motion (BWIM) approach with deep learning (DL) and non-invasive ground-based radar (GBR) time-series data. BWIMs allow site-specific structural health monitoring (SHM) but are usually difficult to attach and maintain. GBR measures the bridge deflection contactless. In this study, GBR and an unmanned aerial vehicle (UAV) monitor a two-span bridge in Germany to gather ground-truth data. Based on the UAV data, we determine vehicle type, lane, locus, speed, axle count, and axle spacing for single-presence vehicle crossings. Since displacement is a global response, using peak detection like conventional strain-based BWIMs is challenging. Therefore, we investigate data-driven machine learning approaches to extract the vehicle configurations directly from the displacement data. Despite a small and imbalanced real-world dataset, the proposed approaches classify, e.g., the axle count for trucks with a balanced accuracy of 76.7% satisfyingly. Additionally, we demonstrate that, for the selected bridge, high-frequency vibrations can coincide with axles crossing the junction between the street and the bridge. We evaluate whether filtering approaches via bandpass filtering or wavelet transform can be exploited for axle count and axle spacing identification. Overall, we can show that GBR is a serious contender for BWIM systems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electric wheel-drive multi-axle heavy-duty vehicles have the characteristics of strong maneuverability and good passability, thereby they are widely used in heavy equipment transportation. However, current research on the composite braking of multi-axle heavy-duty vehicles is rare, which is not conducive to improving braking performance and braking energy utilization efficiency. This work proposes a multi-mode composite braking control strategy for the five-axle distributed electric wheel-drive heavy-duty vehicle. Firstly, given the differences in braking dynamics between two-axle vehicles and multi-axle vehicles, the brake dynamics characteristics of multi-axle vehicles are analyzed, and the vehicle dynamics model of multi-axle vehicles is constructed. Next, a multi-mode composite braking control strategy including a fully electric braking state and hybrid electro–hydraulic braking state is proposed in order to improve the braking energy recovery and braking stability. Finally, a hardware-in-the-loop simulation system is established, and the single-braking conditions and China heavy-duty commercial vehicle test cycle-heavy truck (abbreviated as CHTC-HT) are conducted to verify the performance of the braking control strategy. The results indicate that the recaptured braking energy and braking stability are significantly increased by applying the control strategy proposed in this work. [ABSTRACT FROM AUTHOR]

Enhancements in the structural and operational aspects of transportation are important for achieving high-quality mobility. Toll plazas are commonly known as a potential bottleneck stretch, as they tend to interfere with the normality of the flow due to the charging points. Focusing on the automation of toll plazas, this research presents the development of an axle counter to compose a free-flow toll collection system. The axle counter is responsible for the interpretation of images through algorithms based on computer vision to determine the number of axles of vehicles crossing in front of a camera. The You Only Look Once (YOLO) model was employed in the first step to identify vehicle wheels. Considering that several versions of this model are available, to select the best model, YOLOv5, YOLOv6, YOLOv7, and YOLOv8 were compared. The YOLOv5m achieved the best result with precision and recall of 99.40% and 98.20%, respectively. A passage manager was developed thereafter to verify when a vehicle passes in front of the camera and store the corresponding frames. These frames are then used by the image reconstruction module which creates an image of the complete vehicle containing all axles. From the sequence of frames, the proposed method is able to identify when a vehicle was passing through the scene, count the number of axles, and automatically generate the appropriate charge to be applied to the vehicle. [ABSTRACT FROM AUTHOR]

Important biological processes, such as signaling and transport, are regulated by dynamic binding events. The development of artificial supramolecular systems in which binding between different components is controlled could help emulate such processes. Herein, we describe stiff‐stilbene‐containing macrocycles that can be switched between (Z)‐ and (E)‐isomers by light, as demonstrated by UV/Vis and 1H NMR spectroscopy. The (Z)‐isomers can be effectively threaded by pyridinium halide axles to give pseudorotaxane complexes, as confirmed by 1H NMR titration studies and single‐crystal X‐ray crystallography. The overall stability of these complexes can be tuned by varying the templating counteranion. However, upon light‐induced isomerization to the (E)‐isomer, the threading capability is drastically reduced. The axle component, in addition, can form a heterodimeric complex with a secondary isophthalamide host. Therefore, when all components are combined, light irradiation triggers axle exchange between the macrocycle and this secondary host, which has been monitored by 1H NMR spectroscopy and simulated computationally. [ABSTRACT FROM AUTHOR]

The effect of non-metallic inclusions on the fracture behavior of LZ50 railway axle steel at high temperature was studied by combining experiment and finite element method. The evolution process of the micro void initiation, growth and coalescence was observed, and the strain characteristics around the void were analyzed. It is found that the non-metallic inclusions are broken or debonded from the matrix to form micro voids during deformation. The strain around the void is enlarged and concentrated, leading to void growth and coalescence; then, the continuity of the matrix is destroyed to make the fracture occur in advance. The effects of initial void morphology on the matrix fracture behavior were further studied. It is found that the larger the initial void diameter, the closer the axial distance is to the center of the specimen, the easier the matrix is to fracture. However, changing the radial position of the void has little effect on the matrix fracture behavior. When multiple voids exist, void coalescence is likely to occur, which will intensify the discontinuity of the matrix and accelerate the matrix fracture. [ABSTRACT FROM AUTHOR]

The axle load limit represents the maximum permissible mass that an axle can carry when a vehicle is operating on a road. This limit is closely associated with the expenses incurred in highway construction, truck transportation, and other related sectors. Consequently, it needs to be determined by carefully weighing the relevant costs. As freight demand continues to rise, many rural roads have failed to meet the requirements for maximizing the social benefits derived from truck transportation in China. To address this issue, this study examines the optimization of the axle load limit for rural roads, taking into consideration advancements in road construction technology, construction funding, and vehicle manufacturing techniques. Initially, the entities affected by the axle load limit, namely, road agencies, truck companies, commodity producers, and consumers, are analyzed. Subsequently, a programming model is developed to optimize the truck axle load limit for rural roads, aiming to maximize the cost gap between the scenarios with the incremental limit and those without the incremental limit. Finally, a case study is conducted to validate the effectiveness of the model, using the rural road network in Guiyang city (China) as an illustrative example. The findings indicate that a limit below 17 tons results in a greater increase in benefits compared to costs. However, if the limit increases to 17 tons, the benefit increment decreases to a smaller value than the cost increment. In conclusion, the optimal axle load limit for the rural road network in Guiyang should be 13 tons, at which point the system cost reduction is maximized, resulting in an annual amount of 17.94 million RMB. • Identify the entities involved in the axle load limit in multiple markets. • Analyze the impact mechanisms of changes in axle load limit on the input costs of each entity. • Establish models to measure the direct impacts of the increment in axle load limit. • Modify the input‒output table to assess the spillover effects of the changes in axle load limit. • Expand application of input‒output table. [ABSTRACT FROM AUTHOR]

The measurement of bridge deflection induced by a motor vehicle is an effective way of verifying the weight of the vehicle, and even of determining the layout of its axles. If the vehicle’s weight and the impacts of its individual axles are known, deflection measurements can be used to verify the stiffness of the bridge structure and to evaluate the effectiveness of steel-concrete composite span integration. The bridge in this case study had been specially permanently adapted to carrying very heavy loads, generated by overweight transports reaching the total weight of a few to over 10 MN. The results of measurements of span deflections induced by a heavy vehicle and the way they were used to assess the weight of another overweight transport unit crossing the bridge are presented in the paper. The existing strengthening of the bridge has been found to be universal and effective for various overweight transports. [ABSTRACT FROM AUTHOR]

This scientific article presents a comprehensive examination of vibration frequency characteristics pertaining to wheelset axles, crucial components in railway systems. By exploring the significance of vibration frequency research in railway engineering, we aim to contribute valuable insights into the operational integrity and safety of railway vehicles. Building upon existing studies, our investigation delves into specific parameters related to axle vibration frequencies. With potential applications in axle and wheelset design, our research seeks to advance the efficiency and safety of modern railway transportation systems. [ABSTRACT FROM AUTHOR]

In order to improve the tooth surface geometric accuracy and transmission quality of the axle bevel gear, a machining errors correction method based on one dimensional probe was proposed, which minimized the geometric deviations of the tooth surface from the point of view of mathematical analysis and engineering reverse. The mathematical relationship among the theoretical design tooth surface, actual machining tooth surface and deviation tooth surface were established. The mapping relationship between the machining parameters of the machine tool and the tooth surface deviations was derived. On this basis, the machining correction model of the machine tool was constructed, and the minimization of tooth surface deviations was realized by adopting the numerical iteration inverse solution method. Through the correction experiment of tooth surface machining errors of an axle bevel pinion, the correctness and practicability of the correction method proposed in this paper were verified. The experimental results show that after correction, the maximum machining errors of the pinion convex and concave surfaces are reduced from 0.134 9 mm to -0.012 7 mm, from 0.241 1 mm to 0.031 6 mm, respectively, and the overall deviation trends of the pinion tooth surface are effectively reduced. [ABSTRACT FROM AUTHOR]

Measuring the axle loads of vehicles with more accuracy is a crucial step in weight enforcement and pavement condition assessment. This paper proposed a vibration-based method, which has an extended sensing range, high temporal sampling rate, and dense spatial sampling rate, to estimate axle loads in concrete pavement using distributed optical vibration sensing (DOVS) technology. Temporal convolutional networks (TCN), which consist of non-causal convolutional layers and a concatenate layer, were proposed and trained by over 6000 samples of vibration data and ground truth of axle loads. Moreover, the TCN could learn the complex inverse mapping between pavement structure inputs and outputs. The performance of the proposed method was calibrated in two field tests with various conditions. The results demonstrate that the proposed method obtained estimated axle loads within 11.5% error, under diverse circumstances that consisted of different pavement types and loads moving at speeds ranging from 0~35 m/s. The proposed method demonstrates significant promise in the field of axle load reconstruction and estimation. Its error, closely approaching the 10% threshold specified by LTPP, underscores its efficacy. Additionally, the method aligns with the standards set by Cost-323, with an error level-up to category C. This indicates its capability to provide valuable support in the assessment and decision-making processes related to pavement structure conditions. [ABSTRACT FROM AUTHOR]

The electro-hydraulic actuator (EHA) system applied in rear axle steering (RAS) is used to steer the rear auxiliary wheels of large commercial vehicles and prevent oversteering. For safety reasons, commercial vehicles reduce the steering angle as the load applied to the rear wheels increases or the speed of the vehicle increases. In this study, we present a well-composed model based design (MBD) of an RAS system employing EHA used in large commercial vehicles. In order to apply loads to the rear of the vehicle to validate the legitimacy of the modeling and to replace the actual model's experiments with the simulations, the rotational speed of the motor obtained in the experiment was input to the motor of the simulation model. The organized formulas of the steering angle based on the structural form were defined to compare the steering angle against both the cylinder displacement of the actual model and the simulated model. We also applied load working on the steering wheel to check the angle difference according to the weight. The organized formulas were applied in the MBD system to compare the results of simulation modeling with the actual experimental values to confirm the modeling's validity. [ABSTRACT FROM AUTHOR]

There has been a growing interest in utilizing modeling techniques to design the scan area of non-destructive testing methods prior to field application. To ensure the safety of railway axles, a non-destructive inspection method that is superior to the existing non-destructive inspection techniques is needed. In this study, the induced potential drop method was applied to the crack detection of the press-fitted axles, and a new ICPD sensor was designed and analyzed through electromagnetic simulation. The crack identification of railway axles using ICPD was performed in the axial and circumferential directions. The results showed that when the crack depth of a press fitted axle is 1.0 mm, the crack can be detected at a distance of 10 mm from the crack using this method, and the cracks in mounted wheelset can definitely detect under condition of frequency of 30 kHz and current of 2 A. [ABSTRACT FROM AUTHOR]

Analysis of overloaded axles has received scant attention during the pavement design process. Such overloaded axles are well known to cause extensive damage to the pavement, though the number of repetitions of such axles is considerably small. This investigation proposes using extreme value distributions to describe the overloaded axles from the axle load data collected from the two National Highways in India. A detailed statistical analysis is carried out under different cases. In the first case, a mixed-normal distribution function is used to describe the entire axle load spectra without explicitly considering the overloading. Different threshold values are chosen for the second and the third cases to consider an appropriate extreme value distribution for analyzing the overloaded data. The right tail region of the axle load data related to overloading is described using Pareto, Burr, and Gamma distributions, while the rest of the data is analyzed using a mixed-normal distribution. The design traffic is estimated for all three cases by calculating the load spectra factor, which uses the moment statistics of the axle load distribution. A significant increase (20%–50%) in the design traffic is observed for the second and third cases. [ABSTRACT FROM AUTHOR]

Hollow axles are critical safety components for high‐speed trains, and the operational safety of the axle is ensured by combining infinite life design and damage tolerance analysis based on ultrasonic testing. The establishment of the ultrasonic inspection interval requires the axle bench test, but it has been a challenge to obtain the initial crack at a determined depth. This paper proposes a method for predicting the transverse crack depth of axles by combining a full‐scale axle bench test with simulation analysis. The monitoring of crack depth is achieved by measuring the cracks on the axle surface. The crack propagation test was conducted to validate the prediction method with good results. The test results demonstrate the potential of crack monitoring methods in axle crack monitoring and provide new ideas for axle safety monitoring. Highlights: A method to analyze the evolutionary pattern of axle cracks is proposed.The morphology of axle cracks tends to be consistent and flattened gradually.The path of crack propagation is the path of the fastest crack area growth.Axle crack depth can be obtained in real time by the measurement of the crack length. [ABSTRACT FROM AUTHOR]

This paper presents the results of research into the cross wedge rolling (CWR) process of axle forgings. The presented results concern the parallel rolling process with two wedges. The use of two parallel wedges is aimed at shortening the tool length (increasing productivity) and reducing the values of wedge opening angles and increasing the forming angles, so that the condition 0.04 ≤ tgαtgβ ≤ 0.08 is maintained to guarantee the highest quality forgings. The article analyses the influence of the design of the double wedge tool on the geometric correctness of the forgings obtained, the value of the failure criterion and the force parameters of the process. The results obtained show that the use of multi wedge tools improves rolling conditions by increasing productivity and reducing the tendency of the material to crack with appropriately selected tool parameters.

Rail corrugation can cause the vibration fatigue failure of the bogie, especially in the metro vehicle. Whereas the existing maintenance limit of rail corrugation is mainly based on operating safety and wheel-rail noise emission and neglects the vibration fatigue failure problems arising from the rail corrugation. It is thus desirable to develop a maintenance limit for rail corrugation from the vibration fatigue failure point of view. Considering that the axle box acceleration spectrum defined in IEC 61373 serves as a basic input for the evaluation of the vibration fatigue life of the bogie, the axle box acceleration thus can be taken as a basic boundary condition for the high-frequency vibration of wheel-rail. This paper thus developed a methodology to determine the maintenance limit based on the axle box acceleration spectrum and the transfer function of the wheel-rail system. In this method, the transfer function was identified by the measured rail corrugation and axle box acceleration. Subsequently, the maintenance limit was derived by the axle box acceleration spectrum defined in IEC 61373 together with the transfer function. The newly developed maintenance limit is considered more reliable to suppress the vibration fatigue failure of the bogie arising from the rail corrugation. [ABSTRACT FROM AUTHOR]

Purpose: This paper aims to investigate the performance of two novel numerical methods, the face-based smoothed finite element method (FS-FEM) and the edge-based smoothed finite element method (ES-FEM), which employ linear tetrahedral elements, for the purpose of strength assessment of a high-speed train hollow axle. Design/methodology/approach: The calculation of stress for the wheelset, comprising an axle and two wheels, is facilitated through the application of the European axle strength design standard. This standard assists in the implementation of loading and boundary conditions and is exemplified by the typical CRH2 high-speed train wheelset. To evaluate the performance of these two methods, a hollow cylinder cantilever beam is first used as a benchmark to compare the present methods with other existing methods. Then, the strength analysis of a real wheelset model with a hollow axle is performed using different numerical methods. Findings: The results of deflection and stress show that FS-FEM and ES-FEM offer higher accuracy and better convergence than FEM using linear tetrahedral elements. ES-FEM exhibits a superior performance to that of FS-FEM using linear tetrahedral elements, showing accuracy and convergence close to FEM using hexahedral elements. Originality/value: This study channels the novel methods (FS-FEM and ES-FEM) in the static stress analysis of a railway wheelset. Based on the careful testing of FS-FEM and ES-FEM, both methods hold promise as more efficient tools for the strength analysis of complex railway structures. [ABSTRACT FROM AUTHOR]

A sparse squared envelope is crucial for efficient and accurate diagnosis of bearing faults. Blind deconvolution (BD) is a well-established sparse feature enhancement method for the diagnostics of rolling bearings. Traditional BD methods, such as minimum entropy deconvolution (MED), are susceptible to random transients, making it difficult to enhance fault features of rolling bearings subject to strong random shocks. Deconvolution methods that take the fault characteristic frequency (or fault impulse period) of interest as an algorithm input parameter, such as maximum second-order cyclostationarity blind deconvolution (CYCBD), can alleviate this deficiency. However, bearing fault features are difficult to be enhanced by these methods when the specified characteristic frequency deviates from the actual value greatly. To overcome these problems, the modified smoothness index (MSI) of the squared envelope is proposed as the objective function of the deconvolution method, and a new BD method is developed to achieve a sparse squared envelope for fault diagnosis of rolling bearings. Furthermore, the methodology is extended to the frequency domain, and another new BD method that utilizes the MSI of the squared envelope spectrum as the objective function is established to achieve a sparse squared envelope spectrum for bearing diagnostics. These two proposed BD methods are robust to random transients and do not require characteristic frequency or impulse period as an input parameter for feature enhancement. The performance of the two proposed BD methods is verified on experimental datasets from two different railway axle bearing test rigs and compared with the state-of-the-art deconvolution methods. The results show that the two proposed methods can effectively enhance repetitive transient features in noisy vibration signals and accurately diagnose different faults of railway axle bearings. [ABSTRACT FROM AUTHOR]

A widely used technique for locating the position of a train during its journey involves electrical detection: on a section of track, the train closes ("shunts") a circuit dedicated to its location via its wheels and axles. The quality of the wheel–rail contact is therefore particularly important for signalling management and traffic control. In this paper, we show that the current flowing through the track circuit induces a permanent modification and a nonlinear, frequency-dependent behaviour of the electrical contact. We propose an analytical expression that describes the evolution of the measured voltage as a function of current and frequency for these nonlinear behaviours. This behavioural law was obtained using experimental measurements on a real train and could therefore be integrated into a global model describing the track system. [ABSTRACT FROM AUTHOR]

Railcar axles are large-size parts manufactured in large batches using forging methods. More efficient methods of manufacturing railcar axles are currently being sought. A promising line of research in this respect is connected with the use of cross wedge rolling (CWR). Nonetheless, there exist no rolling mills that would make it possible to manufacture such large-size parts as railcar axles. A solution to this problem was inspired by the symmetric shape of a railcar axle, which makes it possible to roll this part in two passes using the same tools. Taking advantage of the potential offered by numerical modelling, simulations were made of two rolling processes for producing a railcar axle type BA302, i.e. one process was conducted with the use of two rolls and the other with two flat tools moving in the opposite directions. Numerical results demonstrated that railcar axles produced by the proposed rolling process had neither external nor internal (cracks) defects. The effectiveness of the developed CWR method was ultimately confirmed by the high quality of railcar axles that were produced (in a scale of 1:5) under industrial conditions at the Lublin University of Technology. [ABSTRACT FROM AUTHOR]

Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mechanical couplings in engineering usually use interference fits to connect the shaft and hub. A railway wheel axle is a press fit that is connected by interference and can be subjected to bending stress. In loaded press fits, a high concentration of contact stresses can be generated in the area of the axle-fillet beam, which in most cases leads to the failure of the axle due to fatigue and fretting fatigues. Therefore, it is crucial to determine the ability of the press-fitted joints to provide sufficient frictional resistance that can withstand the loads and torques by evaluating the safety factor, especially when the mechanical or structural system is loaded. In this paper, the contact pressure and stress distribution along the radius of the wheel axle are studied using the analytical calculation of Lame's equation, and the numerical method used is by ANSYS software. It was found that interference fits have a great influence on the connection strength of interference fits, which are directly related to the contact pressure. Increasing the interference increases the contact pressure, which allows higher torque and load capacity to be transmitted. The finite element analysis showed good agreement for the highest interference value of 230 µm with a relative error of 1.4%, while this error increased to the maximum relative error of 14.33% for a minimum interference of 100 µm. [ABSTRACT FROM AUTHOR]

Rigid pavement slabs are erected on a prepared subgrade or foundation layer, providing a hard and continuous surface. Transverse joints made of dowel bars connect them, and longitudinal joints made of tie bars join them longitudinally. This study is an investigation of the impact of soil strength and concrete parameters on the effectiveness of dowel bars in rigid pavements. Moreover, three parameters were examined; California Bearing Ratio (CBR), concrete compressive strength and slab thickness. The analysis was conducted using the Ever FE program and focused on several axle configurations applied to the joint. The results indicate inverse association between the pavement slab thickness and the concrete strength, under the assumption of consistent soil strength. Moreover, an assortment of reduced shear forces on the dowel bars is seen when the soil strength values increase. It indicates that soil strength has a greater impact on the shear load of dowel bars compared to the qualities of concrete. Additionally, the type of axles used and the magnitude of soil strength were shown to have a significant effect on the shear load. [ABSTRACT FROM AUTHOR]

Infrastructure worldwide is facing the challenge of aging bridges and increasing traffic loads. Prolonged serviceability and safety of these structures can be enabled by Structural Health Monitoring (SHM) methods. Knowledge of the actual operating loads is critical for evaluation of the remaining service life. However, direct measurement of the loads is challenging and requires a significant financial investment. Bridge Weigh‐In‐Motion (BWIM) methods use the structural response of bridge structures to determine loads, but generally rely on accurate knowledge of the position of loads as a function of time. Positions can be determined using conventional axle detectors, but their lifetime is limited, and their installation is expensive. To avoid these problems, we propose an improved Virtual Axle Detector (VAD) with Enhanced Receptive field (VADER) that can detect axles for all bridge types using accelerometers that can be placed anywhere along the bridge. The same data set with 3787 train passages recorded on a steel trough railway bridge under real operating conditions was used. Our results show that, in comparison with VAD, VADER reduces the number of undetected axles by over 79% and detects 99.5% of axles with an average spatial accuracy of 4.6 cm. [ABSTRACT FROM AUTHOR]

In an effort to find more cost‐effective and proactive ways to keep bridges in good condition, the use of instrumented vehicles has gained great interest in the last decade. Two bridge components that can wear rapidly are the bearings and the road surface. However, past research on drive‐by monitoring has placed focus mostly on detecting losses of bending stiffness in the bridge deck, while assuming ideal support conditions that may differ from real cases significantly, and ignoring the characterization of the road profile. Even further, the need for specialized vehicles equipped with high‐tech instrumentation, low speeds, or very good road profiles has been a major obstacle preventing its practical implementation. This paper investigates the use of axle accelerations from an ordinary two‐axle vehicle crossing the bridge to quantify the rotational stiffness of the supports and the height of the road irregularities while overcoming the limitations exposed above. In contrast to previous research where the response of the contact point has been derived from other vehicular locations based on complex differential equations of motion, transfer functions are employed here. The key advantage of transfer functions is their simple algebraic form that can be easily calibrated on the field. The road profile is then obtained by subtracting the displacement of the bridge under each axle from the displacement of the contact point. There is one prediction of the road profile per axle but only a unique value of rotational stiffness at each support that will yield the same prediction by both axles. The algorithm is successfully tested with a half‐car traveling at 5, 10, 15, and 20 m/s, over a 15‐m bridge beam model with ISO road classes "A," "B," and "C," for boundary conditions ranging from simply supported to fixed. The solution's robustness to modeling inaccuracies and noisy data is also investigated. [ABSTRACT FROM AUTHOR]

The optimization of mining vehicle rear axle weld joints is a complex procedure. The designs for low-cycle fatigue with peak loads were analyzed using computational models and rig testing. On-road evaluation of high-cycle fatigue was performed with the entire vehicle. The iterative analysis is used in design optimization to minimize design cycle time. In sophisticated fatigue calculations with all affecting factors, FEM is utilized. In fatigue failures using road load data, the present deterministic method yields up to 80% correlations. Some critical failure spots were most likely missed owing to operational variations caused by the randomness and multiaxiality of load transfer in link mechanisms with non-linear elements. The fabricated rear axle housing joints are optimized by comparing damage state estimates using stochastic type and multiaxial equivalent loads obtained using Multibody Simulation. The damage state analysis as MBS input stimulus in FE weld models and bolted designs were compared. [ABSTRACT FROM AUTHOR]

The individual drive of the axles of a vehicle produces a reduction of the axle adhesion, implicitly reducing the total traction force of the vehicle. The paper proposes eliminating load transfer effects by using an algorithm to redistribute the traction effort between the tractive axles equipped with electric traction motors. A case study is presented, using the balancing of the electric traction torque for an electric locomotive, using the load transfer effects compensation. The conclusions can be used to maximise the traction of all types of vehicles, such as trailers, hybrid tractors, large harvesters, and Diesel-electric locomotives. [ABSTRACT FROM AUTHOR]

A growing number of studies have demonstrated the effectiveness and superiority of reverse engineering in using axle box vibration acceleration signals to deduce the operation state of wheelsets. However, there is a lack of discussion and summary on the overall mapping relationship between wheel excitation and axle box response, and there has been no detailed investigation on resonance characteristics of axle box. To address the deficiency, a novel resonant excitation loading method is proposed, which is applied to the vehicle model with flexible wheelset and axle box. Amplitude frequency response (AFR) curve of the resonance characteristics of axle box is obtained. AFR is used to characterise the characteristics of various excitation states of wheel, including wheel polygon, wheel tread flat, and wheel-rail separation state, and the corresponding evolution law is revealed. Finally, through two case studies, the guiding role of axle box resonance characteristics on wheel operation status detection is discussed in detail. Analyses show that mastering the resonance characteristics of axle box is an effective way to deduce the operation status of wheel based on the complex axle box vibration response signal, and it will provide a basis for the quantitative evaluation of wheel local damage. [ABSTRACT FROM AUTHOR]

In the process of mining in open pit mines, haul roads will definitely be needed to make it easier to transport. Haul roads play a very important role in the mining production operation cycle. The quality of Haul roads will be a determining factor in achieving production targets, also influenced by Tool productivity. To determine the load-bearing capacity of vehicles passing on the pavement and foundation layer, it is necessary to consider the road surface with friction between the wheels of passing vehicles, the road surface does not experience an increase and decrease in road surface. The largest conveyance that passes through the road in the form of Hino FM 260 JD with a total unit weight and payload of 84000 lb or 42 tons and the assumption of weight distribution on the front axle by 30% and rear axle by 70%. So Hino FM 260 JD has a wheel load of 14700 lb or 7.35 tons. Based on the results of plotting on the graph obtained the thickness of each layer of road structure, structural planning recommendations using R30 % Clay samples with a CBR value of 36.87% for the surface layer at 8,5 inches thick ; for the top layer of foundation using R40 % Clay samples with a CBR value of 32.11% at 9 inches thick and for the bottom layer using R50 % Clay samples with a CBR value of 29.31% at 9,5 inches thick. [ABSTRACT FROM AUTHOR]

In this study, the new mobile robot structure with N parallel axles was designed and developed, as well as its motion equations derived. It uses several parallel axes, which increase its mobility at different surface conditions compared to similar ones. The number of parallel axes in such robotic systems makes studies of the effect of slip mandatory due to the increase in the wheels' contact area. These effects make a difference in the mobile robot kinematic constraints equations. On the other hand, added parallel axels prepare the capability for motion on rough and uneven surfaces. But the mobile platform requires a suspension system to reduce the effects of oscillations due to the floor. Finally, the dynamics model of a mobile robot obtains by considering the effect of wheels' slips, suspension, and parallel axles using Lagrange equations. The concluded model is simulated for a two-axis mobile robot with four wheels in different surface conditions. It can be seen that the deviation of the robot is eminent, besides that the wheel's slips affect the system performance based on the oor conditions. Consequently, the robot deviation on ice is less than that on loose gravel, while the mentioned deviation on loose gravel is twice. [ABSTRACT FROM AUTHOR]

This study investigates the cross wedge rolling (CWR) process for manufacturing a rail axle in a scale of 1:6. Three cases of the rolling process are modelled numerically: standard rolling, wasteless rolling and rolling from a preform. The rolling cases under analysis are compared in terms of material and energy consumption, forming loads as well as propensity to internal and external defect formation. Using the Cockcroft-Latham criterion and the limits of this criterion determined by the rotary compression test, an assessment was made of the propensity of the material to fracture during the rolling processes analysed. Based on numerical results, standard CWR is selected for experimental verification. Obtained experimental results confirm that CWR is an effective method for producing railcar axles that are free from both internal and external defects. The experimental and numerical results obtained confirm that cross wedge rolling technology can be successfully used under industrial conditions for the production of long axles or shafts. [ABSTRACT FROM AUTHOR]

The traditional traction control system (TCS) based on hydraulic braking only works when the wheels are slipping, which will cause the problem of slow response to extreme slip. In addition, the TCS of four‐wheel‐independent‐drive electric vehicle (4WIDEV) is often based on road adhesion characteristics identification or optimal slip ratio identification to implement active control, which is difficult to achieve in engineering. Aiming at this problem, a practical active TCS is proposed in this paper. Firstly, according to the wheel slip state of the front and rear axles, the dynamic transfer of torque between axles is realized to maintain the vehicle propulsion power. Second, the adhesion conditions between road and tire are classified, and two sets of target slip ratio thresholds are formulated for high and low adhesion pavement, respectively. Then the current road adhesion coefficient is estimated by using the advantage that the in‐wheel motor torque can be obtained in real‐time. Thirdly, the overall framework of the control strategy is established, the logic threshold control algorithm is adopted for tracking the wheel target slip ratio. Finally, the simulation results show that the proposed active TCS can improve the vehicle power and avoid excessive wheel slipping. [ABSTRACT FROM AUTHOR]

Rotaxanes consisting of a high‐molecular‐weight axle and wheel components (macro‐rotaxanes) have high structural freedom, and are attractive for soft‐material applications. However, their synthesis remains underexplored. Here, we investigated macro‐rotaxane formation by the topological trapping of multicyclic polydimethylsiloxanes (mc‐PDMSs) in silicone networks. mc‐PDMS with different numbers of cyclic units and ring sizes was synthesized by cyclopolymerization of a α,ω‐norbornenyl‐functionalized PDMS. Silicone networks were prepared in the presence of 10–60 wt % mc‐PDMS, and the trapping efficiency of mc‐PDMS was determined. In contrast to monocyclic PDMS, mc‐PDMSs with more cyclic units and larger ring sizes can be quantitatively trapped in the network as macro‐rotaxanes. The damping performance of a 60 wt % mc‐PDMS‐blended silicone network was evaluated, revealing a higher tan δ value than the bare PDMS network. Thus, macro‐rotaxanes are promising as non‐leaching additives for network polymers. [ABSTRACT FROM AUTHOR]

A rotaxane crosslinker (RC) is known to toughen the resulting rotaxane crosslinked polymer (RCP) via a stress dispersion effect that is attributed to the movable nature of the crosslinking structure. To evaluate this toughening mechanism in detail, a series of structure‐definite RCs equipped with different axle end structures or different numbers of wheel components were synthesized, and subjected to free radical polymerization with a vinyl monomer to obtain RCPs. Analyses of the obtained RCPs revealed that the size of the axle end structure should be well‐balanced to produce a strong toughening effect, and a [3]rotaxane crosslinker works more effectively than [2]rotaxane to toughen RCPs. The mobility of the crosslinking points, in terms of rotational and flipping movements, was more crucial to toughening the RCP than that of translational movement along the axle. The first observation of the above crucial findings proved the utility of the systematic molecular design used in this study. [ABSTRACT FROM AUTHOR]

Train occupancy detection equipment (usually as Axle Counting Equipment) is an important part of communication-based train control (CBTC) system, and its message latency is one of the most important parameters of Zone Controller. With the development and application of the full-electronic interlocking, the interface between Axle Counting Equipment and interlocking system of urban rail transit has changed from relay method to communication method. This change increases the message latency between Axle Counting Equipment and Zone Controller, and influences the functional and engineering design of Zone Controller. Following the data flow of Axle Counting Equipment, this paper analyzes the composition of the message latency from Axle Counting Equipment to Zone Controller, estimates the message latency with different interface methods, finds out the key process that affects the message latency of Axle Counting Equipment, proposes a technical scheme of direct interface between Axle Counting Equipment and Zone Controller. In the proposed scheme, the message latency is analyzed and simulated by computer. The simulation result shows that the message latency between Axle Counting Equipment and Zone Controller is effectively reduced to 1.0 ~ 2.4 s, which provides a basis for further optimizing the functional design and engineering design of Zone Controller. [ABSTRACT FROM AUTHOR]

The detection of cracks in rotating machinery is an unresolved issue today. In this work, a methodology for condition monitoring of railway axles is presented, based on crack detection by means of the automatic selection of patterns from the vibration signal measurement. The time waveforms were processed using the Wavelet Packet Transform, and appropriate alarm values for diagnosis were calculated automatically using non-supervised learning techniques based on Change Point Analysis algorithms. The validation was performed using vibration signals obtained during fatigue tests of two identical railway axle specimens, one of which cracked during the test while the other did not. During the test in which the axle cracked, the results show trend changes in the energy of the vibration signal associated with theoretical defect frequencies, which were particularly evident in the direction of vibration that was parallel to the track. These results are contrasted with those obtained during the test in which the fatigue limit was not exceeded, and the test therefore ended with the axle intact, verifying that the effects that were related to the crack did not appear in this case. With the results obtained, an adjusted alarm value for a condition monitoring process was established. [ABSTRACT FROM AUTHOR]

In this article, we carried out a study on the behaviour and efficiency of an oscillation-damping system, mounted on the driving axles of railway vehicles to mitigate stick-slip oscillations. The occurrence of the stick-slip phenomenon is particularly harmful in operation because it generates wear on the tread surfaces of the wheels and rails, generates fatigue stresses in the axles and diminishes locomotive performance. To reduce these inconveniences, we proposed installing on the axles a damping system to reduce stick-slip oscillations and studied the behaviour and the efficiency in the operation of this system. [ABSTRACT FROM AUTHOR]