Wheel Material Research Articles

Wear and damage behaviors of wheel-rail with different material matchings under various sand deposition densities of rail top in desert environments

In desert environments, the phenomenon of sand particles depositing on the rail top and contaminating the wheel-rail interface is common because the railway is an open system. This work aimed to investigate the wear and damage behaviors of wheel-rail with different material matchings under various sand deposition densities of rail top in desert environments. The results showed that as sand deposition density increased, adhesion coefficient first decreased sharply and then increased slowly, and finally decreased slowly. It was caused by the combined effect of sand solid lubrication, oxide solid lubrication, and surface roughness of wheel and rail. The oxidative wear increased first, peaking at about 0.2 g/m2, and then decreased, whereas the fatigue wear decreased consistently. For wheel and rail materials with similar hardness, the wheel-rail material matching with high carbon content exhibited excellent anti-wear and anti-fatigue performances. The wear and damage of wheel and rail were relatively mild when the sand deposition density was lower than 0.4 g/m2.

Experimental investigation and numerical analysis of material removal efficiency using abrasive microaggregates in grinding processes of Ti6Al4V

Reducing plastic interactions between abrasive grains and the material being processed improves grinding efficiency and lowers energy consumption. Widening the cutting zone with abrasive grains enhances chip formation and reduces lateral material displacement. This can be achieved by using abrasive microaggregates.The paper presents an experimental analysis of grinding with modified wheels containing abrasive microaggregates. It examines how these microaggregates impact the grinding wheel's surface microgeometry and material removal efficiency. The study measured changes in the number, surface area, volume, and spacing of active contact areas on the grinding wheel active surface. A comparative analysis using the Shos indicator showed that abrasive microaggregates promote the formation of active areas with wide cutting edges perpendicular to the cutting direction.Finite element method simulations confirmed that abrasive microaggregates enhance material removal by widening the micro-cutting zone and increasing lateral resistance, which reduces the formation of flashes along the cutting path. The study also assessed how these surface features impact the roughness of the ground surface. A comparative analysis of roughness parameters showed a statistically significant reduction in surface, volume, hybrid, and functional parameters when using grinding wheels with abrasive microaggregates. This analysis was conducted using bootstrap statistical hypothesis tests.

Investigation on friction and wear behavior of wheel material of wheel-rail: a case study of addis ababa light rail transit

Investigation on friction and wear behavior of wheel material of wheel-rail: a case study of addis ababa light rail transit

Investigation on fatigue parameters in railway wheels using a critical plane model

The contact areas between rail and wheel are critical in determining the performance of rail vehicles. Analyzing the mechanics, materials, tribology, and geometry of the interface is important to understand the contact damage mechanisms, fatigue parameter and fatigue life. Developing a simplified and novel approach to predict crack initiation and fatigue life is key for investigating contact fatigue of rail wheel interaction. This study aims to investigate rolling contact fatigue (RCF) cracks and fatigue life in railroad wheels using Finite Element Model (FEM). Using a proper material model that accounts for plastic shakedown, ratchetting, and cyclic hardening for both the rail and wheel materials, the FEM model is analyzed with the help of Abaqus 2020 tool. The submodelling technique was implemented to reduce computation demand. Stress and strain history outputs extracted from the submodel (at 0 mm, 1.3 mm, 2.6 mm, and 3.6 mm depths) were used to predict critical plane orientation, crack initiation and fatigue life using critical plane models. The orientation of critical (crack) plane was found using a novel MATLAB algorithm by searching for a plane with maximum fatigue parameter (FPmax). The investigation reveals that the location of maximum damage is the subsurface and the crack angles fall within the range of (0°, 40°), (62°, 123°) and (143°, 180°) with a 5 % margin and at a depth of 2.6 mm below the wheel surface. The determined fatigue crack initiation and life at this specific location were 6178 and 7174 cycles, respectively. Predicting the critical zone which is susceptible to shorter crack initiation and fatigue life is a crucial to prevent wheel failure.

The correlation between material deformed microstructure and rolling contact fatigue crack propagation of U71Mn rail when matching with CL60 wheel

Deformed microstructure and rolling contact fatigue (RCF) cracks are the two predominant damage characteristics of the field wheel and rail materials from the cross-sectional view. The proportion of two damage characteristics varied under different operating conditions. Thus, this study aims to investigate the correlation between material deformed microstructure and RCF crack propagation of U71Mn rail when matching with CL60 wheel using a twin-disc testing machine. An initial deformed microstructure layer on U71Mn rail material was first obtained by testing under dry condition, and then the RCF crack propagation tests were conducted under water condition. Results indicated that when the crack depth was smaller than the initial deformed microstructure layer depth, the deformed orientation dominated the crack propagation direction; when the depth of crack propagation towards the matrix exceeded the depth of newly formed deformed microstructure region, crack propagation direction dominated the microstructure deformed orientation. The increase in the initial deformed microstructure layer depth would intensify both the crack length and depth, and also would result in thicker newly formed deformed microstructure region. The Pearson correlation coefficient between initial deformed microstructure layer depth and crack depth was 0.998. The influence of initial deformed microstructure layer depth on wear rate was slightly greater than crack depth.

Performance materials with variations of tractor drive wheel fin angle and low-cost manufacturing analysis

Nowadays, the demand for workers in the agriculture industry has decreased and there is a need for rising mechanization in the agriculture process. The agriculture process that requires mechanization is cultivating. The rice cultivator has to be as light as possible, so requires a lighter material but is also strong enough. The correlation between the rice transplanter tool and the wheels is closely related to soil conditions. The selection of wheel materials is considered based on the characteristics of the planting area. In addition, another influence variable is the angle of the fin in the rice transplanter wheel. Material of rice transplanter wheel has been established, these are 1023 carbon steel sheet, AISI 1020 steel cold rolled, AISI 316 stainless steel. The angle of the fin was varied, these are 30, 35, and 40, this fin will give an effect on the traction result of rice transplanter wheel movement. The combination of lightweight material and the appropriate fin angle of the rice transplanter wheel has the best traction result. As a result of this research, the suitable material for the rice transplanter wheel was carbon steel and the fin’s angle was 30. This research involved a comparison and analysis of material strength under various fin angles. The evaluation of stress criteria was conducted using design values to determine the most reliable final product design. The paper contributes by illustrating how to represent the final decision on the combination of design and materials, incorporating a cost index assessment.

Design of Quenching and Tempering Process and Elucidation of the Relationship between Microstructure and Properties of 20Mn2SiNiMo Bainitic Wheel Steel

The rapid development of train transportation toward higher speed and heavier load requires superior wheel materials with high strength and toughness. Herein, a 20Mn2SiNiMo bainitic wheel steel is developed and bainitic wheels are produced. The quenching and tempering process of bainitic wheels is studied considering the bainitic ferrite content and stability of retained austenite (RA). The quenching process includes water spraying and air cooling. Proeutectoid ferrite can be suppressed during the water‐spraying process. During air cooling, the bainitic ferrite transformation is promoted and the stability of RA is improved with the extension of cooling time. Corresponding microstructure of as‐quenched steel at wheel rim is bainite with different morphologies, martensite, and RA. The evolution of RA at lower and higher tempering temperatures is dominated by carbon enrichment and carbon consumption, respectively. Yield strength of bainitic wheel steel mainly comes from body‐centered cubic phase (containing martensite and bainitic ferrite). The increase of dislocation density and the decrease of effective grain size are beneficial for yield strength improvement. Bainitic packets with various direction, deformation‐induced martensite transformation of RA, and plastic deformation all play an important role in enhancing the toughness of bainitic wheel steel.

Investigation of plastic flow of rail vehicle wheels and its effects on rolling contact fatigue based on a dynamic method

To analyze the plastic flow of wheels and its impact on rolling contact fatigue (RCF), this article proposes a multibody dynamics approach that is simple to model and fast to compute, based on the mechanics of wheel-rail contact and Tresca yield criterion. This method is used to study the plastic flow of the wheels and is validated by comparing it with plastic flow analysis based on the shakedown theory. The study shows that the dynamics indicators of maximum shear stress, adhesion saturation and stress ratio effectively reflect the plastic deformation of the wheel. Additionally, increasing wheel speed and curve radius, and decreasing wheel-rail friction coefficient, can effectively reduce the area and severity of plastic deformation in the wheel. Ignoring the impact of temperature effects on RCF, it is found that the more severe the plastic flow, the greater the likelihood of RCF. That is, alleviating the plastic flow of the wheel can reduce RCF damage in wheels. This approach to managing the health of wheels provides a comprehensive understanding of the interplay between operational parameters and the mechanical behavior of wheel materials, guiding maintenance strategies and operational decisions to enhance safety and extend the lifespan of railway components.

Surface topography prediction of slider races using formed grinding wheel shape and material removal mechanism

Compared with the roughness, the three-dimensional (3D) topography parameters, surface microstructure geometric characteristics and other information can more fully evaluate the grinding quality of the slider raceway surface. In this paper, based on the 3D topography model of the abrasive particle distribution on the surface of the formed grinding wheel, the material removal mechanism between the abrasive particle and the raceway surface is analyzed. With the undeformed chip thickness distribution model as the intermediate variable, the 3D topography model of the slider raceway surface is established, and the model verification is carried out from the roughness and the geometric characteristics of the surface microstructure, respectively. At the same time, the surface microstructure is extracted from the topography model, and the effects of different grinding process parameters on the geometric characteristics such as the height to width ratio, depth to width ratio and distribution density of groove, convex peak and peak valley structures are studied. Results are shown that AS,TH increase from [0.05 0.6 μm] to [0.25 0.8 μm] and FGH grows from [0.11 1.05 μm] to [0.5 1.61 μm] when the grinding depth rises from 1 μm to 4 μm. AS, TH are firstly decreased from [0.17 0.61 μm] to [0.08 0.52 μm] and then increased to [0.26 0.78 μm], and the FGH declines from [0.34 1.01 μm] to [0.16 0.86 μm] and then increases to [0.51 1.38 μm] with the feeding speed is in [25, 28 m/min]. In addition, in the range of grinding wheel linear velocity [28, 34 m/s], the AS,TH decreases from [0.19 0.81 μm] to [0.1 0.55 μm] and the FGH decreases from [0.55 1.6 μm] to [0.2 1.1 μm]. This can prepare for the subsequent research on the impact of the topography characteristics on the friction coefficient and wear amount of the slider raceway surface.

Flutter analysis of a rigid-flexible coupled composite space structure with momentum wheels under thermal load

The communication and observation spacecraft generally consists of the spacecraft body, the composite connecting beams, the working payload and the CMG/momentum wheel for integrated attitude-vibration control. When such complex space structure operates in near-Earth orbit, the sudden change in thermal load may cause a solar flux shock to the structure, which is likely to excite the flutter motion of the structure. The flutter mechanism of a rigid-flexible coupled composite space structure configured with the momentum wheel is investigated. In this study, the heat conduction equation of the composite beam appendage is derived. Then, the dynamic equations of the system influenced by the momentum wheel and composite material parameters are obtained based on the Kane's equations. Using the Routh–Hurwitz stability criterion, the stability boundaries of the flexible appendage are obtained for different composite material parameters, different operating conditions of the momentum wheel, and different attitude angular velocities. Finally, the flutter behavior is analyzed based on the dynamic response of the flexible structure and the flutter stability boundaries are verified.

Computational assessment of ratcheting in rail-wheel contact with solid contaminant

A numerical method for the fast evaluation of ratcheting in solid-contaminated contact between rollers was developed. The physical problem was simplified with a plane-strain half-infinite body, with a distribution of pressure and tangential stress on the contact surface obtained by considering the presence of evenly spaced solid contaminant particles between the contacting bodies. Such a distribution was obtained by an analytical method, which considered the material of the contacting bodies as linear elastic. The stresses under the contact surfaces were calculated using the Boussinesq-Cerruti model. Subsequently, the plastic strain accumulated in the roller after each application of the contact load was calculated by means of a non-linear kinematic-hardening constitutive law, also considering the effect of wear in removing material layers from the surface.First, the effects of the introduced approximations were evaluated. In particular, the error in calculating the plastic strain using contact load distributions from a theory based on linear elastic behavior was evaluated by comparison with the results of finite element models. Subsequently, the method was used to assess the experimental results of previously published studies on sand-contaminated contact between rail and wheel materials. Despite the approximations and indetermination of some model constants, the method was proven to be able to qualitatively explain many of the damage mechanisms related to the interaction of the contacting bodies with the contaminant particles.

СРАВНИТЕЛЬНЫЙ АНАЛИЗ ПРИМЕНЕНИЯ КОНТАКТНЫХ ЖИДКОСТЕЙ В ДЕФЕКТОСКОПИИ НА ПРИМЕРЕ УЛЬТРАЗВУКОВОГО КОНТРОЛЯ ПОВЕРХНОСТИ КАТАНИЯ ЦЕЛЬНОКАТАНОГО КОЛЕСА

Coupling fluids are important flaw detection materials that are used during ultrasonic testing in order to find out acoustic contact between the piezoelectric transducer and the object of control. The paper considers coupling fluids of various viscosities that can be used as a coupling medium for ultrasonic flaw detection. A comparative analysis of the effect of the studied coupling fluids on the sensitivity of the control is carried out, which is determined by the attenuation of the transmitted ultrasonic signal through the roll surface of the car wheelset wheel. The control sensitivity is assessed on the flat and inclined surfaces of the all-rolled wheel. The introduction of ultrasound into the wheel material (steel 2) is carried out by an inclined piezoelectric transducer at an angle α = 900, with an oscillation frequency f = 0.4 MHz. It is found out that by providing a reliable constant force of the ultrasonic transducer P121-90-0.4 due to the permanent magnets built into it, an increase in the viscosity of the coupling fluid can significantly affect the amplitude of the received echo signals. During the research, it is found that low-viscosity coupling fluids are characterized by stable coupling regardless of the time and clamping force of the transducer, in contrast to high-viscosity coupling media, when using them sharp fluctuations in the overall gain of the second through signal in AGC zone are observed on the flaw detector screen. Therefore, in practice, the use of high-viscosity coupling media leads to a sharp increase in signal amplification (amplitude), which may result in over reject.

Review of Magnesium Wheel Types and Methods of Their Manufacture.

This article provides a detailed review of the types of magnesium wheels available in the industry and the current methods of the wheels' production. The past several years have seen a significant development of magnesium-based lightweight alloys employed as a structural material for modern light vehicles. Magnesium alloys are characterized by their low density while maintaining good mechanical properties. The use of these alloys in the industry enables vehicles' weight reduction while increasing their technical parameters. The first part of the article presents the unique properties of magnesium alloys that determine the application of this material for lightweight vehicle wheels. The advantages of using magnesium wheels over aluminum wheels are also presented. Next, a classification of the types of magnesium wheels was made in regard to their construction, applications, and manufacturing methods. At present, magnesium wheels by construction can be classified according to their geometry as single parts or assembled parts. In reference to geometry, wheels can have different shapes: classic, multi-spoke, with holes, or with frames. Depending on the geometry used, magnesium wheels can have different parameters, such as their mounting hole spacing, wheel diameters, or rim width. Considering the applications in various industries, main distinctions can be made between magnesium wheels for automobiles, motorcycles, bicycles, and wheelchairs. Magnesium wheels can also be categorized in regards to the manufacturing methods: casting, machining, forging, and hybrid manufacturing. The second part of the article focuses on the analysis of magnesium alloy wheel-manufacturing technologies used in the industry and developed by research centers. This article discusses these manufacturing technologies in detail and indicates prospective directions for further development.

An automotive steel wheel digital twin for failure identification under accelerated fatigue tests

In this paper, a digital twin to predict failure in automotive steel wheels during experimental fatigue tests is proposed. The methodology involves a wheel finite element model that incorporates assembling and mounting processes, and CDTire/3D simulation package, employed to calculate tyre to rim generalised internal forces in several loading conditions. The two models are decoupled under small deformation assumption, which allows to reduce computational effort for batch simulations. The Digital Twin (DT) is designed to meet the standard requirements and the working principles of test benches for dynamic cornering, radial, and biaxial fatigue tests. The overall DT architecture is described with emphasis on different test bench logic and the introduction of simplifications to efficiently estimate failure under mean stress variation. Then, a simplified formulation of the critical plane McDiarmid multi-axial failure criterion is presented to face the non-proportionality of stress path under loading conditions. Finally, the methodology is validated against an industrial case study: the predicted failures are compared to experimental test result database for wheel topologies, material properties, test benches and loading conditions.

Investigating the Corrosive Influence of Chloride Ions on Slag Recovery Machine Inner Guide Wheel in Power Plants.

An important method that coal-fired power plants use to realise low-cost zero discharge of desulfurisation wastewater (FGD wastewater) is to utilise wet slag removal systems. However, the high Cl- content of FGD wastewater in wet slag removal systems causes environmental damage. In this study, the corrosion behaviour of the inner guide wheel material, 20CrMnTi, was studied using dynamic weight loss and electrochemical methods. X-ray diffraction, scanning electron microscopy, and energy spectroscopy were used to analyse the organisational and phase changes on the surfaces and cross sections of the samples at different Cl- concentrations. The corrosion rate increased with the Cl- concentration up to 20 g/L, but it decreased slightly when the Cl- concentration exceeded 20 g/L. In all the cases, the corrosion rate exceeded 0.8 mm/a. The corrosion product film density initially increased and then decreased as the Cl- concentration increased. The corrosion products comprised mainly α-FeOOH, γ-FeOOH, β-FeOOH, Fe3O4, and γ-Fe2O3.

Initiation and evolution of wheel polygonal wear: Influence of wheel-rail hardness ratios

Railway wheel polygonization is a type of uneven wear of material which worsens the running stability of trains. As a significant factor influencing the wear, wheel-rail hardness matching (i.e., the hardness ratio HW/HR) might affect the formation of a polygonal wheel. Thus, rolling-sliding wear tests were conducted using three wheel steels matching two rail steels to explore the influence of HW/HR (ranging from 0.649 to 1.263) on the initiation and evolution of wheel polygonal wear. The results show that when matching the softer rail, the wheel was less likely to become polygonal with an increase in HW/HR. When matching the harder rail, the wheel presented earlier polygon initiation under a moderate HW/HR of 0.792. The largest HW/HR of 1.263 presented the best anti-polygon condition for wheel material. The wear mechanism of polygonal wheel was dominated by abrasive, fatigue and oxidative wear at the crest and fatigue wear at the trough.

Kinematic and force parameters of an elastic wheel when rolling on a flat rigid surface

The implementation of forces and moments applied to the wheels of a vehicle occurs in the zone of contact of the wheels with the supporting surface, and therefore the analytical determination of their force and kinematic parameters should be based on consideration of the phenomena occurring in contact. One of the directions for solving these problems is based on a technique based on the theory of preliminary displacement of wheel surface elements in the contact zone with the supporting surface and dividing the contact area into adhesion and sliding zones, which makes it possible to take a new approach to the consideration of wheel rolling mechanics. The use of this technique makes it possible to obtain relatively simple equations for such power and kinematic parameters of the wheel as the coefficient of rolling resistance, the coefficient of tangential elasticity of the wheel, and hysteretic losses in the wheel material. The derived equations contain a small number of parameters that can be easily determined experimentally and are convenient for both theoretical and practical use. Comparison of theoretical and experimental results with studies of other authors shows their relatively small discrepancy, which confirms the validity of the research methodology used, as well as the assumptions made.

Investigation of parameters for fault detection of worm gear box using denoise vibration signature

In industrial applications, worm gearboxes are a key element. In a worm gearbox, as the material of a worm wheel is softer than that of a worm screw, the worm wheel gear is vulnerable to failure through various modes like pitting, wearing out, or tooth breakage during the sliding process. Due to this, it is essential to monitor the failure of the worm wheel gear of the worm gearbox, and it has gained importance for the diagnosis of faults in gearboxes. The present work focuses on the investigation of the effect of worm wheel tooth breakage, worm wheel bearing outer race, and varying load on vibration signature amplitude and frequency domain statistical features such as root mean square (RMS), crest factor, kurtosis, mean, peak to peak, skewness, sample variance, and standard deviation. The experimental setup is fabricated to conduct the experimental trials. An OR34 FFT analyzer with NVGate software is used to acquire the frequency domain vibration signature. Experimental results show that captured vibration signature amplitude for healthy worm wheel and bearing increased as fault occurred on the worm wheel, and bearing and frequency domain statistical features value changed with the change in fault location in the worm gearbox.

Two Contributions to Rolling Contact Fatigue Testing Considering Different Diameters of Rail and Wheel Discs

Scaled rolling contact fatigue tests, used to practically simulate the wear of the wheel and rail material under laboratory conditions, are typically classified into two categories. Tests in the first category use twin-disc stands, while the second group of test rigs use two discs of different diameters considering the rail disc as the larger one. The latter setup is closer to the real situation, but problems can occur with high contact pressures and tractions. The focus of this paper is on two main contributions. Firstly, a case study based on finite element analysis is presented, allowing the optimization of the specimen geometry for high contact pressures. Accumulated plastic deformation caused by cycling is responsible for abrupt lateral deformation, which requires the use of an appropriate cyclic plasticity model in the finite element analysis. In the second part of the study, two laser profilers are used to measure the dimensions of the specimen in real time during the rolling contact fatigue test. The proposed technique allows the changes in the specimen dimensions to be characterized during the test itself, and therefore does not require the test to be interrupted. By using real-time values of the specimen’s dimensional contours, it is possible to calculate an instantaneous value of the slip ratio or the contact path width.

ОПРЕДЕЛЕНИЕ ДИАПАЗОНА ЭФФЕКТИВНЫХ РЕЖИМОВ ШЛИФОВАНИЯ И МАТЕРИАЛОВ ШЛИФОВАЛЬНОГО КРУГА ДЛЯ ОБРАБОТКИ СТАЛИ 95Х18

The development of a mathematical model for the grinding treatment of steel 95X18 with recommended grinding wheels, namely a wheel of silicon carbide green, el’bor wheel, diamond wheel is discussed. When studying the influence of grinding modes and grinding wheel materials during the processing of 95X18 steel on the roughness of the treated surface, a multifactorial experiment was carried out. The roughness of the treated surface was evaluated according to the Ra parameter, using a portable profilometer of the MarSurf PS1 model. Based on the data obtained, it is possible to choose the optimal cutting mode based on the required roughness of the treated surface. It has been established that in order to achieve a stable quality of the treated surface Ra 0.63, it is necessary to use a diamond wheel at cutting speeds from 10 to 25 m / s and low feed rates. The obtained regression equations showed that an increase in the cutting speed or a decrease in the feed led to a decrease in the roughness of the treated surfaces. The main provisions of the metal cutting technology and the mechanical engineering technology were used.