High Wheel Research Articles

Enhancing road safety of PLEVs by novel vehicle concepts: A comprehensive investigation on regulations, accident statistics, and perception of riders in Europe.

The rise of Personal Light Electric Vehicles (PLEVs), including electric bicycles and electric kick scooters, represents a relevant trend in current urban mobility. PLEVs offer economic, social, and environmental advantages, making them increasingly attractive for short-distance travel. Despite their benefits, concerns about the safety of PLEVs, particularly related to road accidents, have arisen due to their growing presence in urban areas. This paper examines various aspects of PLEV safety, focusing on equipment required by regulations, circulation aspects, and users' needs; based on such highlights, the objective is to derive a vehicle concept (in the form of a kick scooter) that integrates elements for PLEV safety maximization starting from the design phase. A review of PLEV-related regulation in European countries, and particularly for electric kick scooters, is initially provided to determine the mandatory equipment for their circulation in the widest possible number of countries. Analysis of accident data for PLEVs in the EU then reveals critical factors contributing to the occurrence of crashes, injuries, and casualties, as well as the type and severity of riders' injuries. Surveys on user perceptions shed light on safety concerns of daily riders, indicating the most relevant aspects to enhance from the user's perspective. Based on these findings, the study proposes a novel electric kick scooter concept integrating safety features derived from regulations, accident analysis, and user needs. Safety equipment aimed at increasing riding stability (high diameter wheel, pneumatic tyres) appears as the most promising solution for maximizing PLEV safety. Inclusion of turning light indicators can also increase riding stability, since the user can exhibit his/her intention of turning while maintaining the contact with the handlebar; as of today, this latter feature is mandatory only in Italy among all EU countries. The work additionally emphasizes the need for harmonized regulations, enhanced safety standards, specifically designed infrastructure, and user awareness campaigns to improve PLEV safety. This research is functional for the proposal of a sustainable and safe transportation solution that can increase the consensus towards PLEVs and the consequent spread of electric microvehicles.

Cu-doped nanocomposite Pr2Fe14B/α-Fe ribbons with high (BH)max

Abstract The melt-spun ribbons of nominal composition Pr9Fe84.2–x B6.2P0.3Zr0.3Cu x (x = 0, 0.5, 1, 2) were prepared at wheel speeds of 21 m·s−1, 27 m·s−1, 30 m·s−1, and 33 m·s−1. The XRD patterns show that as the wheel speed increases, the crystallinity of the 2:14:1 hard phase decreases, while that of the α-Fe soft phase increases. The (BH)max, remanence, and coercivity are improved from 63 kJ·m−3, 0.85 T, and 515 kA·m−1 for the Cu-free ribbons to 171 kJ·m−3, 1.08 T, and 684 kA·m−1 with x = 0.5. The high squareness ratio of J r/J s ∼ 0.82 at 0.5 at.% Cu (27 m·s−1) indicates strong exchange coupling due to small grain sizes of 15 nm and 30 nm for soft and hard magnetic phases, respectively. The SEM images revealed smooth morphology and uniform element distribution at 0.5 at.% Cu (27 m·s−1), contributing to the high magnetic properties. The low recoil permeability (μ rec) value of 5.466 × 10−4 T/kA·m−1 to 1.970 × 10−4 T/kA·m−1 confirms the strong exchange coupling with x = 0.5 (27 m·s−1). The initial magnetization curves show that the coercivity mechanism of the Cu-free alloy evolves from the nucleation of the reverse domain to the domain wall pinning as the wheel speed increases, resulting in a high coercivity value of 818 kA·m−1 (33 m·s−1). Conversely, for the Cu-added alloy, the coercivity mechanism changes from pinning to the nucleation of the reverse domain from low to high wheel speed.

Asphalt pavement structural competency during staged airfield runway construction strategy

ABSTRACT This paper reports the results from a full-scale evaluation of asphalt pavement structural competency during a multi-stage construction strategy. The staged pavement construction included three stages: (1) new conventional asphalt pavement, (2) unpaved full depth reclaimed (FDR) pavement, and (3) thin surface asphalt paved FDR layer. The full-scale pavement sections consisted of a standard and substandard pavement structural design. The accelerated pavement testing (APT) experiments were executed by simulating the loading conditions of an aircraft with a critical combination of relatively high wheel load and high tire inflation pressure. The structural capacity of the pavement test items was monitored using a falling weight deflectometer. From this study, the staged pavement construction concept was found to be a potential approach to extend the service life of asphalt pavements. Unpaved FDR layers are structurally competent to support a low volume of aircraft operations. These findings support the transition to the use of asphalt pavements containing an FDR layer from an experimental to routine rehabilitation practice for airfield asphalt pavements.

A Meta Analysis of Whole-Body and Heart Mass Effect Sizes From a Long-Term Artificial Selection Experiment for High Voluntary Exercise

Effect sizes are a quantitative measure of the magnitude and direction of a phenomenon. These estimates can be compiled across multiple studies to summarize the weight of evidence for a particular alternative hypothesis, which is generally termed a meta-analysis. A meta-analytic approach allows one to summarize information from a wide array of similar studies and reach conclusions that may not be apparent on a case-by-case basis (e.g., to determine the overall effectiveness of a drug). Meta-analyses may be particularly useful in selection experiments, where the magnitude of a correlated response is necessarily expected to increase across generations, perhaps eventually reaching a plateau. Here, we examined the effect of artificial selection for high voluntary wheel running on heart mass in mice, which was expected to increase with selection for aerobic exercise behavior. The experiment spans nearly 30 years and 100 generations. All 4 of the replicate High Runner (HR) lines reached selection limits around generations 17-27, running approximately 2.5-3-fold more revolutions per day than the 4 non-selected Control (C) lines. These selection limits cannot be explained simply by a complete loss of heritability. Functional studies have tried to elucidate subordinate traits that affect motivational and/or ability for endurance exercise and have shown that HR mice differ from C in several other behavioral, physiological, and morphological traits. Several studies of heart ventricle mass have reported larger values in HR mice (with body mass as a covariate), but the differences often do not reach statistical significance (p<0.05). We compiled Least-Square Means, standard errors, F-statistics, degrees of freedom, and p-values from multiple studies. We also recorded pertinent information, such as: covariates used, age, generation, and whether other main effects were present (e.g., sex, wheel access). We calculated a common measure of effect size (Pearson’s R) and associated confidence intervals. This work is part of a larger meta-analysis to quantify effects of selection on various traits across multiple levels of biological organization. Preliminary results indicate that, despite a lack of statistical significance in many generations, HR mice have evolved larger hearts and smaller bodies relative to Controls. Moreover, a plateau in effect sizes for both of these traits coincide with the generational range during which the selection limit for wheel-running behavior was reached. NSF IOS-2038528. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Design method for warship flight deck structures subjected to high temperature and wheel loads

Design method for warship flight deck structures subjected to high temperature and wheel loads

NetWheels: A Web Application to Create High Quality Peptide Helical Wheel and Net Projections

NetWheels: A Web Application to Create High Quality Peptide Helical Wheel and Net Projections

Investigation on the mechanism and measures of derailment of empty freight train passing a turnout in the diverging route

The derailment of railway vehicles at a turnout is a worldwide concern. However, the derailment of empty freight trains in the switch section of a turnout in the diverging route is rarely concerned. Therefore, in order to analyse the derailment mechanism of empty freight trains in the turnout switch area and to propose appropriate preventive measures, field investigation and dynamic simulation of the derailment are carried out on the basis of an empty freight train derailment in the turnout switch area of the diverging route. Firstly, the background of the derailment is presented and the potential influencing factors of the derailment are analysed according to the field investigation. Secondly, a detailed train-turnout dynamic model is established, taking into account the variable cross-sections of the turnout switch rail and the effect of the longitudinal coupler force. Thirdly, based on the model, the derailment mechanism of the empty freight train is revealed through theoretical analysis and simulation calculation. Finally, the effect of the potential derailment influencing factors is analysed and preventive measures are proposed to reduce the derailment risk of the empty freight train at the turnout switch area in the diverging route. The results indicate that this derailment is caused by the combined effect of the inherent structural characteristics of the switch, the large longitudinal coupler force, and the high wheel rail friction coefficient. The possibility of derailment can be reduced by reducing the longitudinal coupler force and the wheel rail friction coefficient. In addition, the installation of a guard rail in front of the turnout can effectively prevent empty freight train derailment in the turnout area.

Grinding of Cemented Carbide Using a Vitrified Diamond Pin and Lubricated Liquid Carbon Dioxide

Despite extensive research on grinding of cemented carbide, few studies have examined abrasive machining of this material using small-diameter super abrasive tools (also known as grinding pins/points), especially with respect to varying cooling-lubrication methods. This study therefore focuses on a comparative experimental investigation of three such methods - dry, emulsion, and lubricated liquid carbon dioxide (LCO2-MQL). The performance of these methods and the resulting grindability are examined in terms of grinding forces, force ratios, specific energy, and through the analysis of wheel loading. The results show that LCO2-MQL grinding has lower grinding forces (normal forces – 8 % to 145 % lower than dry grinding, and 18 % to 33 % lower than emulsion grinding and tangential forces – 4 % to 66 % lower than dry grinding and 28 % to 78 % lower than emulsion grinding) and specific energy 24 % to 51 % lower compared to dry grinding and 64 % to 69 % lower than emulsion grinding, indicating its potential for efficient material removal. However, a challenge with high wheel loading was observed with LCO2-MQL, likely due to the lack of oxygen in the CO2 grinding atmosphere. Despite this issue, the LCO2-MQL method shows potential for efficient operations, especially at higher aggressiveness values where the lowest specific energies were achieved. These results provide new insights into various aspects of cooling-lubrication methods in the pin grinding of cemented carbides.

Cover crops and soil loosening are key components for managing P and C stocks in agricultural soils

AbstractAgricultural soils have accumulated phosphorus (P) and lost carbon (C) in the recent decades. Simultaneously, soil structure has been degraded by the large increase in machinery weight. High wheel loads compact the subsoil, resulting in reduced root growth, decreased yields, and hence decreased C inputs and P removals. To reduce the accumulated excess P stock, the P balance should be kept strongly negative for decades, which requires high biomass production. P accumulation in poorly yielding field parts has created local hotspots, often characterized by soil compaction and poor drainage. They may be only 1%–6% of the agricultural landscape area but present a high risk for waterbodies. Identifying and targeting these hotspots for P removal can be a key strategy for mitigating P emissions. Achieving the P removal is most likely to require soil loosening to repair the damage caused by compaction and use of cover crops to mine out the accumulated P. This soil improvement strategy can also be beneficial for C sequestration and crop productivity. This commentary highlights the current status and recent developments in the interactions between compaction, cover crops and P loss to provide a research basis for developing landscape‐level strategies.

Optimisation of turnout frog profile geometry using revenue service wheel profiles

Railroad turnouts are an essential element of the track infrastructure that facilitates the movement of trains between adjacent or diverging tracks. Turnout frogs are subjected to high wheel impact forces due to the inherent need for a discontinuity in their geometry. To develop an optimised frog geometry to minimise wheel impacts, a parametric study was designed and executed that considered three critical design parameters: point (i.e. nose) slope, relative height difference between wing and point, and longitudinal wing slope. Four hundred wheel profiles were extracted from a dataset of one million revenue service wheel profiles based on a wheel classification methodology previously developed. Wheel impact was quantified for each frog geometry case based on wheel transfer distribution and vertical wheel trajectory which were analysed using a developed Python algorithm. A total of 30 unique geometries were evaluated, including the existing standard design geometry for a N.A. heavy point conformal frog. Results demonstrated that each parameter affects different locations along the frog and total impact is most affected by point slope. Lastly, an optimised frog geometry was selected that ensures well-distributed wheel transfer locations preventing the concentration of damage, and results in low total impact at the transfer point.

Impact of rail joints on the local stresses in crane runway girders

Vertically acting wheel loads from overhead bridge cranes and potential additional horizontal crane loads induce global stresses due to bi-axial bending and torsion and local stresses in crane runway girders which mainly affect the girder’s web. The latter typically represent one of the most decisive criteria for the fatigue design check of welded girders and are the focus of this paper. Crane rails with foot flange are typically used for moderate to high wheel loads. They are usually connected to the top flange with rail clips. Rails with foot flange are used with and without elastomeric bearing pads between the rail and the top flange of the girder. The local stresses in the webs of crane runway girders are strongly affected by discontinuities of the crane rails. Such discontinuities can originate from unplanned rail cracks as well as planned rail expansion joints. The current mechanical models for concentric as well as eccentric wheel loading in relevant design standards assume continuous crane rails. However, rail joints are expected to significantly increase the local stresses in the region beneath rail joints. The present paper focuses on the impact of rail joints on the local stresses in crane runway girders. The research activities comprise experimental tests as well as numerical parametric studies based on finite element calculations, both for rails with and without elastomeric bearing pads. The aim of the investigations is to develop a better understanding of the mechanical behaviour and to quantify the increase factor for maximum local stresses in order to avoid future fatigue damage due to an unexpected increase of local stresses at a rail joint.

Recent Advances in Wayside Railway Wheel Flat Detection Techniques: A Review.

Wheel flats are amongst the most common local surface defect in railway wheels, which can result in repetitive high wheel-rail contact forces and thus lead to rapid deterioration and possible failure of wheels and rails if not detected at an early stage. The timely and accurate detection of wheel flats is of great significance to ensure the safety of train operation and reduce maintenance costs. In recent years, with the increase of train speed and load capacity, wheel flat detection is facing greater challenges. This paper focuses on the review of wheel flat detection techniques and flat signal processing methods based on wayside deployment in recent years. Commonly used wheel flat detection methods, including sound-based methods, image-based methods, and stress-based methods are introduced and summarized. The advantages and disadvantages of these methods are discussed and concluded. In addition, the flat signal processing methods corresponding to different wheel flat detection techniques are also summarized and discussed. According to the review, we believe that the development direction of the wheel flat detection system is gradually moving towards device simplification, multi-sensor fusion, high algorithm accuracy, and operational intelligence. With continuous development of machine learning algorithms and constant perfection of railway databases, wheel flat detection based on machine learning algorithms will be the development trend in the future.

High cerium content (Nd-Pr-Ce)2Fe14B melt-spun ribbons with high coercivity

The effects of wheel speeds on the magnetic properties and microstructures of [(Nd,Pr)1–xCex]-Fe-B melt-spun ribbons were investigated. Compared to melt-spun ribbons with low cerium (Ce) content (x = 0.2), amorphous formation can be suppressed at high wheel speed in the ribbons with a relatively high Ce content (x = 0.8), and with the increase of the wheel speed, the magnetic properties of the ribbons with high Ce content raise continuously. At high wheel speed, the coercivity mechanism of melt-spun ribbons is mainly pinning field, and the high wheel speed introduces a large number of defects into the matrix as pinning sites. Furthermore, ribbons with high Ce content form a fine and uniform grain structure, so the grain boundary area enlarges, which further hinders the movement of domain walls. The combined effects of the above factors enable ribbons with high Ce content to have excellent magnetic properties (Hcj = 0.977 T, Mr = 64 m2 A/kg) at the wheel speed of 35 m/s.

Formation mechanisms and three-dimensional characterization of composite inclusion of MnS-Al2O3 in high speed wheel steel

Formation mechanisms and three-dimensional characterization of composite inclusion of MnS-Al2O3 in high speed wheel steel

Study on railway curve squeal using a rigid-flexible coupling model of vehicle and track

Squeal noise occurring in narrow curves is one of the most annoying noise issues for people living by the railway track. When vehicles pass through those curves, squeal noise is mainly generated due to the large, high-frequency, lateral sliding friction force. To investigate generation mechanism of curve squeal, a three-dimensional (3D) vehicle-track interaction model with a flexible wheelset and a flexible curved track is built in a multi-body simulation tool in this paper. Compared to conventional rigid models, this model allows to obtain the high frequency friction force between wheel and rail. This calculated friction force in the frequency domain is analyzed to identify the major modes. Those modes are compared with the modal properties of the wheelsets and rails in order to determine which of their modes have the main contribution to the friction force and the squeal noise. In addition, a parametric study is performed to study the influence of vehicle speed, curve radius, wheel/rail friction coefficient and further parameters on the dominant modes of friction forces.

COMPOSITE BRIDGES WITH CRACKED CONCRETE DECK SPANNING BETWEEN TRANSVERSE BEAMS UNDER FATIGUE SHEAR LOADING

AbstractFor concrete deck of large steel‐concrete composite road bridges cracking occurs due to tension because of negative bending moments at the support area, at the same time traffic load with high wheel loads passes the deck spanning between transverse beams. They induce cyclic shear loading in the cracked concrete deck. In composite bridges the application of prefabricated concrete elements has led to economical designs with a benefit in construction time. In this case, the prefabricated concrete elements are supported by the transverse beams when the on‐site concrete is poured. For this construction, the concrete is subjected to tension forces resulting from the global load‐carrying effect, which needs to be superimposed with local effects as wheel loads acting as shear fatigue loading. In this paper, the fatigue strength of cracked concrete deck under tension and shear fatigue loading is discussed.

Running performance analysis of a passenger coach with small-radius wheels in the diverging route of a turnout

Small-radius wheels are gradually introduced on special rail vehicles, such as double-decker coaches and piggyback wagons. It allows for a low-floor design and further increases the loading capacity of vehicles. From the perspective of vehicle dynamics, small-radius wheels have lower unsprung mass than the nominal wheels with a radius of 460 mm, and it could mitigate the wheel-rail dynamic interaction. Also, the contact patch size is reduced due to the increased curvature of the rolling contact circle, and they are more sensitive to changes in the track geometry than nominal wheels, especially in turnouts with discontinuous rail profiles. To investigate the dynamic response of small-radius wheels in a turnout, the Manchester Benchmark passenger coach with variable radius wheels and a left-hand turnout with a radius of 245 m are introduced in this work. The influence of wheel radii on the running performance, including the wheel-rail interaction and wheel damage behaviour, is investigated by numerical simulations. In addition, a sensitivity study is executed to evaluate the influence of unsprung mass and wheel flange friction on the performance of a vehicle whose wheel radius is 275 mm, and the potential remedy to mitigate high wheel wear is proposed.

Dislocation density and shear texture effects on grinding force during the grinding of maraging steel 3J33

This paper focuses on the change of dislocation density and shear texture generated in plastic deformation, and its effect on the grinding force during the grinding of maraging steel 3J33. The grinding force in a grinding arc is divided into three stages, i.e., rubbing, plowing and chip forming in turn, and each grinding arc is continuous. The large plastic deformation caused by the forming force of cutting has a significant effect on the nearest rubbing force in the next arc area by influencing the microstructure. However, it has little effect on the plowing force away from the cutting area. Therefore, a flow stress model with respect to the influence of dislocation density and texture was established to describe the relationship between the grinding forces of different grinding arcs and modify the total grinding force. The microstructure of the processed materials before and after grinding experiments was compared, and the corresponding shear texture, Taylor factor and dislocation density were analyzed. The analysis of the multi-stage forces composed elastic deformation and plastic deformation of offers a comprehensive understanding of dislocation density and shear texture evolution mechanisms during the grinding process that would be very beneficial for process optimization. At high wheel speed, lower workpiece speed and cutting depth could result in higher rubbing force, thereby achieving better polishing effect and lower surface roughness.

Research on detection of different metallographic structures of high speed wheel steel based on laser-induced breakdown spectroscopy.

The laser-induced breakdown spectroscopy (LIBS) experimental platform was applied to obtain LIBS spectral the data of 10 CL60 wheel steel samples. The principle component analysis (PCA) was used to preliminarily analyze the macroscopic characteristics of LIBS spectral data. With the spectral intensity and spectral intensity combined with spectral intensity ratio as variables, three spectral correction methods including median filtering, baseline correction and multiple scattering correction (MSC) were used for pretreatment. And the support vector machine (SVM) qualitative model was established to determine the metallographic structure. It was found that the SVM model established by using the pre-processed data of MSC as the input variable has the best effect. The accuracy rate of calibration set is 100%, and the accuracy rate of prediction set is 98.4%. The research has shown that LIBS combined with SVM model can be used for discriminant analysis of different metallographic structures of train wheel steel.

Mice from lines selectively bred for voluntary exercise are not more resistant to muscle injury caused by either contusion or wheel running.

Muscle injury can be caused by strenuous exercise, repetitive tasks or external forces. Populations that have experienced selection for high locomotor activity may have evolutionary adaptations that resist exercise-induced injury and/or enhance the ability to cope with injury. We tested this hypothesis with an experiment in which mice are bred for high voluntary wheel running. Mice from four high runner lines run ~three times more daily distance than those from four non-selected control lines. To test recovery from injury by external forces, mice experienced contusion via weight drop on the calf. After injury, running distance and speed were reduced in high runner but not control lines, suggesting that the ability of control mice to run exceeds their motivation. To test effects of injury from exercise, mice were housed with/without wheels for six days, then trunk blood was collected and muscles evaluated for injury and regeneration. Both high runner and control mice with wheels had increased histological indicators of injury in the soleus, and increased indicators of regeneration in the plantaris. High runner mice had relatively more central nuclei (regeneration indicator) than control in the soleus, regardless of wheel access. The subset of high runner mice with the mini-muscle phenotype (characterized by greatly reduced muscle mass and type IIb fibers) had lower plasma creatine kinase (indicator of muscle injury), more markers of injury in the deep gastrocnemius, and more markers of regeneration in the deep and superficial gastrocnemius than normal-muscled individuals. Contrary to our expectations, high runner mice were not more resistant to either type of injury.