Wheel Fatigue Research Articles

Multi-objective optimisation of a metro wheel profile to reduce wheel flange wear and RCF considering the distribution density of wheel−rail contact points

In this study, the problem of severe wheel flange wear and tread rolling contact fatigue (RCF) of metro wheels with two wheel profiles, i.e. the LM-30 profile and the DIN5573-30 profile, is investigated. The contact characteristics of the two profiles are compared to analyse the causes of wheel flange wear and RCF. Indices combining the density distribution of contact points are proposed to evaluate the wheel flange wear and RCF. The optimisation region of the wheel profile is defined by eight arc parameters, which is derived from the tangency of the arcs. A back-propagation neural network is constructed as a surrogate model for the design variables and the objective function. Four intelligent optimisation algorithms are compared and used to solve the optimisation problem. The vehicle—track dynamic model and the wheel wear and RCF prediction model are used to verify the performance of the optimised profile. The results show that the critical speed of the optimised profile is between that of the LM profile and that of the DIN5573 profile, and the curving performance of the optimised profile is significantly improved. At the same time, the optimised wheel profile can reduce wheel flange wear and tread RCF.

Online identification methods for low-order wheel polygons coupled with axle cracks

Wheel polygons pose a threat to the safety of train operations due to wheel fatigue, necessitating online identification. The online identification of wheel polygons predominantly relies on the axle box vertical nx (n-multiple integer of axle rotation frequency) signals generated by wheel polygons. The low-order vertical nx signals are easy coupling to other faults like axle cracks, leading to errors in wheel polygon identification. A signal decoupling method is crucial for removing the crack components from the vertical nx signal to obtain more accurate identification results for low-order wheel polygons. Employing principles of signal superposition for different faults, this article proposes a method to decouple the wheel polygon nx signal from the vertical nx signal by subtracting the crack-related portion. This method has been validated through an ABAQUS + SIMPACK online rigid-flexible coupling model, indicating that it significantly improves the accuracy of wheel polygon identification. The 1x amplitude of the decoupled signal decreased by 60.78%, and the 2x amplitude decreased by 55.79%.

Structure Design and Driving Dynamics Research of Crane Wheel Fatigue Test Device

In order to explore the fatigue damage of the crane wheel, the contact stress between the crane wheel and the steel rail was calculated. Moreover, the fatigue mechanism of crane wheels was also discussed by deriving the theoretical wheel pressure formula. As a result, a device design idea based on the fatigue mechanism of the crane wheel was proposed, where the device can be used to detect the bearing capacity, wear resistance and fatigue resistance of crane wheels. By using the simulation methods, the structure requirements and driving dynamics of the test device for different wheel diameters and wheel pressures were investigated and validated. Finally, the structural diagram of the fatigue test device is presented to provide the design guidance for the experiment research of the fatigue properties and reliability of crane wheels.

A rapid method to predict biaxial fatigue life of automotive wheels using proper orthogonal decomposition and radial basis function algorithm

This paper presents a rapid method for predicting the biaxial fatigue life of automotive wheels using a combination of proper orthogonal decomposition and radial basis function algorithm. Currently, numerical simulations of biaxial fatigue tests are being developed to evaluate wheel performance. However, these simulations are computationally expensive due to the need to simulate multiple discrete loading cases within a given biaxial spectrum. To address this issue, we propose a novel approach that utilizes proper orthogonal decomposition and radial basis function algorithm to improve computational efficiency. By leveraging high-fidelity simulation results from a small number of loading cases, a reduced order model is constructed to accurately predict the tire-rim interface force fields required for wheel strength calculations. The reduced order model significantly reduces the computational time by 65.4% for simulating all loading cases, while maintaining a maximum predicted error of less than 2% compared to the high-fidelity model. Subsequently, the predicted interface forces are mapped onto the rim surface for strength calculation, and the wheel fatigue life is determined using the Brown-Miller multiaxial damage criterion. Comparative analysis with experimental results demonstrates the desirable accuracy of our method in simulating the stress-strain history, crack initiation position, and minimum fatigue life of the wheel. Overall, the proposed method offers a powerful tool for the rapid fatigue analysis of spectrum-loaded wheels, providing an efficient and accurate means of predicting biaxial fatigue life.

Numerical investigation of premature fatigue of high-speed train wheels in presence of facets defect with case study

In this paper, the premature failure of the high-speed railway wheel of power locomotive commissioned in Morocco since 2018 was investigated. A three-dimensional model of the wheel is established, with account of specific wheel's features, to perform the finite elements and modal analysis. Simulations were conducted for several functional diameters of wheels (850mm, 885mm, and 920mm) to figure out stress distribution in different operation conditions. Stress results show that the wheel bears the mechanical loading in both exceptional and fatigue loads, therefore a modal analysis of the structure in presence of facets, which create a vibratory state, is done to examine their effect on the premature fatigue of the wheel. Modal analysis reveals that the presence of facets leads to a vibratory mode near to resonance. Based on those results, critical operation points as function of facets number and wheel diameter were determined to avoid scenarios that lead to cracks and premature fatigue of the studied wheels. Existing maintenance procedures must be modified to overcome this problem and increase the wheel's lifetime without affecting the operation safety of the high-speed train.

A Review of the Rolling Contact Fatigue of Rail Wheels Under Various Stresses

A Review of the Rolling Contact Fatigue of Rail Wheels Under Various Stresses

Effect of Residual Stresses on Wheel Fatigue Life and Experimental Validation

Steel wheels, consisting of rims and spokes, are important load-bearing parts of vehicles, and the fatigue fractures’ life estimation accuracy directly determines the stability and safety when applied in the transportation industry. The most common form of failure is fatigue fracture. The strong elastic–plastic deformation during the rim roll-forming process generates a residual stress field in its surface layer, which changes the actual stress distribution in the rim when it is loaded and thus affects the fatigue life of the steel wheel. In this paper, ABAQUS software was used to establish a rim-rolling simulation model to obtain the residual stress field distribution after forming and compare it with the actual residual stress on the formed surface of the rim to verify the reliability of the model. On the basis of this model establishment, the service hazard areas and maximum stresses of steel wheels with or without superimposed residual stress fields were calculated separately, and their fatigue lives were predicted separately using the local stress-strain method. The simulation results show that the maximum stress of the rim before and after the superimposed residual stress occurs in the area of the bottom of the groove, which is consistent with the actual failure location. However, the maximum stress after superposition increased from 120.7 MPa to 332.9 MPa, and the corresponding calculated life decreased from 158,340,000 to 459,500 cycles, which is closer to the actual test results. The results of the study can provide a theoretical basis for the lightweight design and process improvement of automotive steel wheels.

Validation of machine learning approaches for estimating wheel fatigue loads at the front suspension of a race car during track driving

AbstractThe wheel loads of a race car have been estimated in view of structural durability assessments. First, the front left double‐wishbone suspension of a rear‐wheel‐drive race vehicle has been instrumented; then, wheel loads have been estimated by means of four approaches: (i) a geometric matrix (GM) method, (ii) a feedforward neural network (FNN) approach applied to the fully instrumented suspension (FIS), (iii) a FNN approach involving a reduced number of sensors (the partially instrumented suspension (PIS)) and an inertial measurement unit (IMU), and (iv) a linear modeling approach (LM). After having trained the FNNs by using suspension signals acquired in a racetrack as inputs and related tire forces measured with the GM method as targets, the FNN‐based methods have been validated on three different racetracks by comparing the estimated loads with those estimated by means of the GM method. According to the results achieved, the FNN approaches are effective for the estimation of the wheel forces.

ПОСТРОЕНИЕ КРИВЫХ ГЛУБИННОЙ КОНТАКТНОЙ УСТАЛОСТИ ПОВЕРХНОСТНО УПРОЧНЕННЫХ ЗУБЧАТЫХ КОЛЕС

Laws of fatigue resistance changes of surface-hardened toothed gears are established. It is shown that the main criterion of serviceability of gear wheels of transmissions of power-saturated machines is deep contact pitting of active surfaces of teeth. Dependence is investigated between the number of cycles before the deep contact destruction of material and the maximal tension of cycle with taking into account the mechanical characteristics and structural parameters in the critical zones of the diffusion layers of the teeth, in which fatigue processes of deep contact destruction of material are developed. Lines of deep contact fatigue of teeth material are constructed by the criterion of equality of hardness value and structural parameters in the zones of fatigue processes development under cyclic contact loading. It is shown, that the deep contact fatigue of gear wheels hardened to a considerable degree is determined by hardness value and structural components of local volumes of teeth subsurface layers. Slope index of the deep contact fatigue lines of gear wheel material have been determined. Correlation coefficients and equations of linear regression have been obtained for each deep contact fatigue line depending on hardness value in the subsurface dangerous zone of the diffusion layer, in which formation and development of fatigue processes occur, leading to the limit state of the highly stressed gear wheels.

Multi-Objective Profile Design Optimization to Minimize Wear Damage and Surface Fatigue of City Train Wheel

Wear and fatigue of wheels have a great effect on the maintenance of railway vehicles and running safety. In the case of an urban railway where no rail lubrication system is installed, it is reported that the risk of wheel damage is high in curved sections. In the present study, we intended to present a method of designing a wheel profile of city trains that can minimize wear and fatigue in curved sections, using the multi-objective optimization method. In multi-objective optimization, we explored a wheel profile design that can reduce wear and fatigue of wheels at the same time, while also satisfying the design performance constraints, such as the safety against derailment and contact force between rails and wheels. A multi-body dynamic analysis was conducted for design performance evaluation, and the best wheel profile design was produced utilizing the analysis result. A wheel profile with minimized wear, a wheel profile with minimized surface fatigue, and a wheel profile with both minimized wear and surface fatigue that can improve the performance of city train wheels were presented respectively using a Pareto-optimal Solution, which is the result of multi-objective optimization. The running safety performances such as derailment and lateral force of the optimized wheel profiles showed improved characteristics when compared to those of the initial wheel profile.

Effects of Axle Configuration on Third Type of Rolling Contact Fatigue of Wheels of High-power AC Locomotives

Effects of Axle Configuration on Third Type of Rolling Contact Fatigue of Wheels of High-power AC Locomotives

Multiscale fatigue-prediction method to assess life of A356-T6 alloy wheel under biaxial loads

The real stress of a car wheel can be reproduced by biaxial tests. However, in the cases of complicated loads, these tests are expensive and time-consuming. Additionally, shrinkage cavities and uneven microstructures can be introduced in A356 cast aluminum alloys, which has a certain influence on fatigue life. Therefore, a new simulation method for the biaxial wheel fatigue test, including the effects of the shrinkage cavity and secondary dendrite arm spacing (SDAS), is urgently needed to avoid the dispersion of the simulation results and reduce costs. In this paper, a new multiscale biaxial fatigue simulation method is proposed. An efficient tetrahedral mesh data-mapping algorithm is developed, in which the natural coordinates are introduced, and transfer of the SDAS and porosity between the cast wheel and finished wheel are realized. Based on the meso-cell model and stress-gradient theory, a mesoscopic fatigue-strength prediction method with defects and SDAS effects is developed. The two pieces style fatigue strength surface is determined. S-N data prediction methods driven by the coupling model and data and solely by the data are developed respectively. The generalization accuracy is within 4%, the structure of the pure data model is simple. The prediction accuracy is verified by performing a uniaxial tensile experiment. A wheel biaxial simulation model is established, and a continuous biaxial load is realized using the sequence amplitude curve family. Finally, a new multiscale biaxial fatigue simulation method with multiple load spectra is created using Fe-safe. The prediction result for the minimum life starting point (considering casting defects) is consistent with the test results, and the overall prediction results are significantly improved. The proposed method lays a solid foundation for optimization design and Big Data fatigue prediction of aluminum alloy wheels.

DETERMINATION AND ANALYSIS OF TECHNICAL PARAMETERS OF THE BENCH FOR RAILWAY WHEELS COMPLEX TESTS

Purpose. The purpose of the work is to determine and analyze the technical parameters of the bench for railway wheels complex tests, providing for the combination of fatigue and contact strength tests, their simultaneous performing on same test-bench. Methodology. Determination of the technical parameters of the test-bench was carried out based on comparing the characteristics of fatigue and contact strength tests of railway wheels. Requirements for fatigue tests and related equipment are determined based on an analysis of the current regulations and patent review. A model of the contact strength test-bench with the introduction of necessary changes in terms of ensuring the cyclicity of the working effort application was adopted as the basic model for the development of a complex test-bench. The criterion for the possibility of complex tests, involving the simultaneous testing of railway wheels for fatigue and contact strength, was the dependence of the test-bench roller diameter on the parameters of the tested wheel, the wheelset axle load, which includes the tested wheel and the wheel material endurance limit. Findings. The analysis of the obtained dependence showed that the roller diameter as a function of the load in the contact zone of the “wheel – roller” pair has second order discontinuity in the section where this load changes from the minimum to the maximum value. Analytical dependence is also presented and analyzed in graphical form. The generalization of the results obtained made it possible to conclude that it is impossible to carry out complex tests of railway wheels, which provide for the combination of fatigue strength tests with contact strength tests, subject to their simultaneous holding at the same test-bench. Originality. For the proposed scheme of the bench for complex tests of railway wheels, for the first time, we obtained the dependence linking the parameters of the test wheel, the parameters of the bench, the wheel pair axle load and the wheel material endurance limit. Practical value. The results obtained can be used as a basis for the development of new test-benches for railway wheels.

Physics-based data-driven interpretation and prediction of rolling contact fatigue damage on high-speed train wheels

Rolling contact fatigue (RCF) of high-speed train wheels is detrimental to reliability and entails huge maintenance costs. Accurate prediction of RCF damage is important for train operators, however, physics-based methods are not suitable for practical applications. Based on accumulated RCF data, this paper develops a physics-based data-driven method for the interpretation and prediction of RCF damage risk. First, based on RCF mechanism, it is found that many relevant parameters can be used for RCF prediction. Then, eight predictors are extracted from RCF-related data through dimensionality reduction methods, including linear discriminant analysis and kernel Fisher discriminant analysis. It shows that greater wheel out-of-roundness or smaller wheel diameters leads to higher RCF risks; previously defective wheels are more likely to reencounter RCF damage; the RCF risk varies in different seasons; the effect of wear on RCF damage is significantly nonlinear. Afterwards, a predictive model is established based on logistic regression. Validation results yield an average accuracy of 75% and also demonstrate its easy interpretability, fast computational speed and stable performance. Further, test result shows an accuracy of 85% to distinguish high-risk wheelsets prior to RCF inspections. The proposed method can be applied to the risk-based maintenance of high-speed train wheels.

The Effect of Spent Fluid Catalytic Cracking Filler on Performance Testing of Asphalt Concrete Mixture

The spent fluid catalytic cracking (SFCC), waste from the petroleum industry, is nonstop increasing and causing environmental pollution in Vietnam. This study is an attempt to recycle SFCC in pavement construction. The study investigated the effect of SFCC, as a filler material in the hot‐mix asphalt (HMA), on the essential characteristics of the asphalt concrete mix. First, the optimum percentages of bitumen and SFCC rate were investigated based on the Marshall design method. The HMA with SFCC showed more enhanced stability, flow, and other Marshall properties than the asphalt concrete mixture with the optimum limestone filler of 5%. Besides, the effects of SFCC rates on Marshall characteristics were explored. Second, performance tests were conducted to compare the mix with the different optimum content fillers of SFCC, limestone, and Portland cement. The tests include wheel tracking, indirect tensile, fatigue, and dynamic modulus tests to evaluate the performance of HMA with SFCC. It was found that the asphalt mixture with the optimum SFCC filler content can enhance pavement performance and improve the rutting and cracking resistance of the asphalt pavement.

Reliability Analysis of Wheel fatigue strength based on active learning Kriging Model

The reliability analysis of fatigue strength of rail vehicle wheels is studied in this paper. On the basis of deterministic analysis, a basic model for reliability analysis of wheel fatigue strength is established by comprehensively considering many uncertain factors. A reliability analysis method based on active learning Kriging (ALK) model is introduced to solve the fatigue strength failure probability of wheels. The results of reliability analysis are verified, and the results show that the reliability analysis based on ALK model can significantly improve the efficiency on condition the accuracy is guaranteed.

Influence mechanism of large inclusion on wheel fatigue crack

In this paper, the formation mechanism of wheel rim crack and control technique was investigated. Feature of wheel rim crack and aggregated attachments on the inner wall of nozzle were examined through scanning electron microscope and energy dispersive spectrometer. Metal rheological test of round billet rolling was conducted to investigate the corresponding location of large inclusions in the round billet and in the wheel. It was found that the rim crack of wheels during service is caused by large inclusions that originated from the aggregated inclusions on the inner wall of the nozzle. According to Murakami’s modelling, the critical size of the inclusions that initiate cracks relates to the depth from the tread. The critical sizes of the inclusions for cracks initiation at 10 mm, 14 mm, 16 mm and 20 mm below the tread are about 0.1 mm, 0.2 mm, 0.5 mm and 1.5 mm, respectively. Process optimization was made with combination of a series methods. Dispersed annular venting stopper was adopted to block the aggregation and attachment of inclusions on the inner wall of nozzle. Current and frequency of electromagnetic stirring in mold were increased to restrain the impact depth of molten steel flow and inclusions. Cooling intensity of the secondary cooling was decreased to reduce the probability of inclusions captured at the solidification front. After optimization, the number of large inclusions was greatly reduced by more than 80%, and the number of inclusions larger than 1 mm is greatly reduced from 35% to 8%. The risk of wheel rim cracks occurrence could be reduced greatly.

Material comparison of dynamic cornering fatigue test (iso3006) for automotive wheel rim

With the technological advancement in the automotive sector, the vehicles are crossing their limits in every aspect. Hence, the subsequent improvement related to the wheel and braking of the vehicle is very crucial as the wheel carries the whole weight of the vehicle in dynamic and harsh environmental conditions. ISO-3006 is a comprehensive test for wheel standardization, and the dynamic cornering fatigue test is a part of this standard. This test investigates the wheel fatigue under bending torque. When a car turns, the bending moment is applied to the wheel via drive axle. In this paper, we investigate the test on a designed wheel with five different materials via ANSYS software. As the wheel weight has a direct impact on vehicle performance, selecting lighter materials is extremely important. The result of this research indi-cates the area of maximum fatigue stresses, and also it provides a comparison between five popular materials for the wheel rim considering the fatigue life and weight of the wheel. Finally, it is shown that carbon fiber reinforced plastic (CFRP) has the most fatigue strength con-cerning its lightweight.

Effect of niobium and molybdenum addition on the wear resistance and the rolling contact fatigue of railway wheels

Brazilian heavy-haul railway companies have drawn extensive research in the last years for developing solutions that can make the operation in this area more efficient and safer, such as friction management, the use of new mechanical assemblies, and the use of new materials for wheels and rails. Another solution implemented is increasing the weight transported by train wagons; however, the more weight added, the more deterioration caused to wheels and rails, for example, promoting higher maintenance costs and risks to safety. Thus, the key to extending the life cycle of railroad wheels is to reduce the wear and rolling contact fatigue (RCF) in developing new materials and in manufacturing them. Niobium (Nb) and molybdenum (Mo) are usually added to increase the mechanical strength of pearlitic steels by decreasing the interlayer spacing. This way, comparative twin-disc test for wheel material under dry conditions was performed to verify the wear resistance of a commercial railway wheel (7C) and a newly developed class D railway wheel steel (7 M) with Nb and Mo addition. Following the specifications of the Association of American Railroads (AAR) standard, a twin-disc tribometer with automatic control of load and speed was used. The slip ratio was obtained from the difference between the axis rotation. 7 M steel was observed to present lower mass loss compared with 7C steel. The Magnetic Barkhausen noise analysis showed higher residual stress close to the surface for 7 M steel, which correlated with the work-hardened depth. Such results, therefore, indicate that 7 M steel presented better performance than 7C steel regarding the specific characteristics of the tests. To confirm the feasibility of the wheel material for use in service, further twin-disc tests are proposed for both wheel materials (7 M & 7C) against the same rail material.

Effects of Molybdenum Addition on Rolling Contact Fatigue of Locomotive Wheels under Rolling-Sliding Condition.

Rolling contact fatigue (RCF) damages often occur, sometimes even leading to shelling on locomotive wheel treads. In this work, the RCF damage behaviors of two locomotive wheel materials with different molybdenum (Mo) contents were studied, and the influence of depth of wheel material was explored as well. The result indicates that with the increase in the Mo content from 0.01 wt.% (wheel 1, i.e., a standard wheel) to 0.04 wt.% (wheel 2, i.e., an improved wheel), the proeutectoid ferrite content and the interlamellar spacing of pearlite decreased, the depth and length of the RCF cracks increased and the average RCF live of locomotive wheel steel improved by 34.06%. With the increase in the depth of material, the proeutectoid ferrite content and the interlamellar spacing of pearlite increased, the depth of RCF cracks increased, the length of RCF cracks of wheel 1 increased and then decreased whereas that of wheel 2 decreased, the RCF live showed a decrease trend for wheel 1, while the RCF life increased and then decreased for wheel 2. The processes of shelling can be divided into three patterns: cracks propagating back to the surface, crack connection and fragments of surface materials.