Wheel Model Research Articles

Dynamic characteristics of wheel–rail collision vibration for high-speed train under crosswind

ABSTRACT This paper focuses on the dynamic characteristics of wheel–rail collision vibration for high-speed train under crosswind. The wind load model is established by using fast Fourier transform harmonic synthesis method and Davenport coherence function, the lateral displacement of wheelset of high-speed train under crosswind is calculated, the dynamic model of wheel–rail collision vibration system of high-speed train under crosswind is established. The effects of vibration frequency, wheel–rail clearance and lateral damping on the characteristics of wheel–rail lateral clearance impact vibration system of high-speed train are discussed. Numerical simulation results show that the impact velocity of wheelset collision on left and right rails increases with the increase of vibration frequency. When ω > 3.3, the system changes from chaos state to single period stable state through inverse doubling bifurcation; when b < 0.0033, it is in a chaos state, and with the increase of b, the inverse doubling bifurcation occurs until the hunting motion of the wheel–rail system is in a stable state; when , the system is in a stable single period operation state, and with the continuous increase of , it begins to have hop bifurcation, enters a multi-period and chaos state, and finally it is in a stable single period operation state.

Design and performance analysis of an adaptive omnidirectional wheel for heavy payload robot

PurposeWith the development of automation technology, the accuracy, bearing capacity and self-adaptation requirements of wheeled mobile robots are more and more demanding under various complex conditions, which will urge designers such shortcomings as the low accuracy, poor flexibility and weak obstacle crossing ability of traditional heavy haul vehicles and improve the wear resistance and bearing capacity of traditional omnidirectional wheels.Design/methodology/approachThe optimal configuration for heavy payload transportation is obtained by building sliding friction consumption model of traditional wheels with different driving types based on Hertz tangential contact theory. The heavy payload omnidirectional wheel with a double-wheel steering and a coupled differential wheel driving is designed with the optimal configuration. The wheel consists of a differential gear train unit and a nonindependent suspension unit. Kinematics model of the wheel is established and relative parameters are optimized.FindingsThe prototype experiments show that the wheel has higher motion accuracy and environment adaptability. The results are consistent with the theoretical calculation, which show that the accuracy is more than 50% higher than that of differential prototype. The motion stability and the accuracy of the coupled differential omnidirectional wheel are better than those of the traditional omnidirectional wheels during the moving and obstacle crossing process under complex conditions, which verifies the correctness and advantages of the design.Originality/valueAiming at the specific application of heavy payload omnidirectional transportation, a new omnidirectional mobile mechanism with a two-wheel coupling drive structure and an adaptive mechanism is proposed. The simulation and experimental results show that it can realize the high-precision heavy-load omnidirectional movement, the effective contact with the ground and improve the adaptability to the rugged ground. It is flexible, simple and modular and can be widely applied to transportation, exploration, detection and other related industrial fields.

Surface prediction in laser-assisted grinding process considering temperature-dependent mechanical properties of zirconia ceramic

Zirconia ceramics are widely applied in many advanced applications in various fields, including biology, aerospace, manufacturing, owing to its outstanding biocompatibility, excellent wear and chemical resistance, and improved toughness over traditional ceramics. Laser-assisted grinding (LAG) is considered as a potential hybrid machining process for low-damage machining of hard and brittle materials (HBMs). In the meanwhile, surface topography and roughness are important indicators to evaluate the surface integrity during the grinding operation. In this study, a grinding wheel model considering stochastic process is established. The thermal distribution of laser irradiation is calculated, and thus the theory for calculation of the critical depth of plastic region (dc) under the influence of laser, which also considers the changes of temperature-dependent mechanical properties is described systematically. Based on the aforementioned models, the predictive model of the surface topography for LAG process was proposed. Subsequently, a series of experiments were designed and implemented. The results indicate that the experimental results have a good agreement with that of the simulated surface topography. The error rates of surface roughness Rz and Ra between the simulated and experimental results are both <8 %. In the meantime, as the laser power increases, plastic mode starts to dominate material removal, and thus the surface integrity is obviously improved. The depth of median crack is also significantly reduced, which can help to reduce the sub-surface damage. Lastly, average power density (Iave) is defined to evaluate the selection of machining parameters.

A car wheel energy harvesting system regarded as a robotic kinematic chain system

The aim of this article is the mathematical modeling of the car wheel with an energy harvester. The car wheel will be represented as a 3-DoF robotic kinematic chain. The Matlab program has been used to simulate the movement of the car wheel and the movement of the electromagnetic energy harvester located on the tire of the wheel. Simulation of the movement of the energy harvesting element allows us to compute the energy harvested in such a system.

An iterative optimization algorithm for posture and geometric parameters of grinding wheel based on cross-section sensitivity and matching constraints of solid end mills

Grinding wheel posture and geometric parameters are the key to optimizing the grinding process for helical grooves of solid end mills. However, the current envelope calculation models have not done enough research on the influence of the grinding wheel discretization method and grinding kinematics models mainly focus on helical grooves with constant core radius. Moreover, the matching error of the overall cross-section curve is ignored. These problems can reduce model generality, affect final calculation results, and cause inferior cutting performance. Therefore, a novel optimization algorithm for grinding wheel posture and geometric parameters is developed in this paper. Firstly, a parametric grinding wheel modeling method with adaptive adjustment of control variables is proposed, and a generalized grinding kinematics model for variable core radius is established. Then, by analyzing the sensitivity of cross-section parameters and the formation mechanism of the core radius, an iterative strategy based on parameter sets is established. Under the condition that the core radius is ensured in advance, the matching errors of rake angle, groove width, and overall cross-section curve are considered comprehensively to optimize the grinding wheel posture and geometric parameters. Finally, the proposed method is verified by simulation and machining. The results indicate that the proposed method can realize the envelope calculation of the helical groove with variable core radius, and optimize the grinding wheel posture and geometric parameters accurately and efficiently.

Design of Customized Pnuematic Wheel

The modern wheel of a car is defined as a circular section intended to rotate the axle bear. To meet market demand, original equipment manufacturers use the latest technology to design and manufacture wheels. Advanced technology that assists in the production of wheel rims is computer aided design (CAD) software and software analysis. In this paper we have used CAD and analytics software to the best of their ability. Wheel modeling was done using SOLIDWORKS and was submitted to ANSYS for analysis work. The ANSYS system is used to reproduce various strengths, component weight tracking and to validate and review results. The solution mode in the ANSYS system calculates bending times, pressures, and shifts in their relationships without manual intervention, reducing the relative time and scientific calculation strategy by the person. The dry analysis work of the ANSYS was performed by considering the Polyamide Imide material with different geometry (suggestions 1, 2, 3, 4, 5, 6) and their related functionality have been observed respectively. In this outcome paper Proposition 6 met the requirement and suggested prototyping. Keywords: ANSYS, SOLIDWORKS, Stress Analysis,

An investigation into the effect of resilient wheel stiffness on the dynamic behaviour of a metro vehicle running along a tangent track

Resilient wheels are extensively used for trams due to the noise reduction they can achieve. However, the effect of the resilient wheels on vehicle dynamics has not been adequately studied. An effort is presented in this paper, trying to bridge this gap. To simulate interactions between vehicle and track, the resilient wheel is modelled as a multi-rigid body system consisting of a rigid wheel core and a rigid rim between which a rubber layer is inserted. The rubber layer is regarded as three-directional spring-damper units, allowing the rim and core to have relative motions, so that the flexibility of the resilient wheel provided by the rubber layer is fully simulated. Then, the dynamics of a vehicle-track coupling system integrated with this resilient wheel model is simulated and compared with in-situ measurement. The simulation results show that, compared with a conventional solid wheel, the vertical vibration of the wheel core is much reduced in the frequency range of 70–300 Hz while the lateral vibration is much reduced in the frequency range of 90–300 Hz. The paper continues with the recommendation of the radial and axial stiffnesses, two key parameters of the resilient wheel, aiming to lower the wheel-rail contact force and carbody vibration.

Effect of design and material on structural rigidity of automobile wheel - an optimisation approach

An automobile wheel plays a vital role in supporting the tyre and the entire weight of any vehicle. This study aims to examine the distribution of stress and deformation across 5-twin-spoke and multi-spoke wheel designs whilst varying lightweight materials, as well as optimise the base designs of the wheel such that they reach an optimum level. The wheel was modelled using SolidWorks, before being analyse by Finite Element Analysis software whereby aluminium and magnesium alloys were assigned. The structural rigidity of the wheel models was assessed by conducting static structural analysis and radial fatigue analysis. Changes in terms of total deformation, von-Mises and alternative stress were obtained, and tabulated. Optimisation of the wheel models was conducted by making necessary modifications to the base designs. The result shows that multi-spoke fared better than 5-twin-spoke in both analyses, and the notable weak point observed is the hub region. In term of material-wise, it was found that Magnesium AZ91D alloy generally has higher deformation, von-Mises and alternating stress than Aluminium 6061 Alloy. Future works could be focused more on conducting additional tests so that the wheel models are well-geared for road usage, such as impact and cornering fatigue tests.

A Simple and Inexpensive Running Wheel Model for Progressive Resistance Training in Mice

A Simple and Inexpensive Running Wheel Model for Progressive Resistance Training in Mice

A Simple and Inexpensive Running Wheel Model for Progressive Resistance Training in Mice.

Previously developed rodent resistance-based exercise models, including synergistic ablation, electrical stimulation, weighted-ladder climbing, and most recently, weighted-sled pulling, are highly effective at providing a hypertrophic stimulus to induce skeletal muscle adaptations. While these models have proven invaluable for skeletal muscle research, they are either invasive or involuntary and labor-intensive. Fortunately, many rodent strains voluntarily run long distances when given access to a running wheel. Loaded wheel running (LWR) models in rodents are capable of inducing adaptations commonly observed with resistance training in humans, such as increased muscle mass and fiber hypertrophy, as well as stimulation of muscle protein synthesis. However, the addition of moderate wheel load either fails to deter mice from running great distances, which is more reflective of an endurance/resistance training model, or the mice discontinue running nearly entirely due to the method of load application. Therefore, a novel high-load wheel running model (HLWR) has been developed for mice where external resistance is applied and progressively increased, enabling mice to continue running with much higher loads than previously utilized. Preliminary results from this novel HLWR model suggest it provides sufficient stimulus to induce hypertrophic adaptations over the 9 week training protocol. Herein, the specific procedures to execute this simple yet inexpensive progressive resistance-based exercise training model in mice are described.

New multiple regression and machine learning models of rotary desiccant wheel for unbalanced flow conditions

In this study, five Multiple Linear Regression, three Multilayer Perceptron Regressor, seven Decision Tree and four Support Vector Machine models were constructed to predict outlet temperature and humidity ratio of silica gel desiccant wheels using eight input parameters for unbalanced flow condition. The effect of different kernel functions of Support Vector Machine algorithms, on the modeling of desiccant wheel was investigated for the first time in the open literature. Detailed validation of the developed models showed that the Response Surface model outperformed other Multiple Linear Regression models, and the Support Vector Machine model with Pearson VII Universal kernel was the best among all models. The determination coefficient and root mean square error for temperature were found to be 0.9791 and 1.2832 °C for the Response Surface model and, 0.9984 and 0.3511 °C for the Support Vector Machine model with Pearson VII Universal kernel, respectively. In the case of humidity ratio, the corresponding statistical parameters were 0.9763 and 0.5672 g/kg for the former and, 0.9976 and 0.1810 g/kg for the latter. The proposed models can be used reliably in the analysis of solid desiccant-based air conditioning systems for design and energy analysis.

Analysis of the effectiveness of Corporate Social Responsibility in brand marketing with AAKER Brand Equity and Daisy Wheel Models

Corporate Social Responsibility (CSR) have a great capacity to influence society to create that good brand equity. In light of this, many organizations now have ardent reputation in promoting CSR activities in the interest of society. Through review of related studies and survey questionnaires to both staff and customers of Accra Breweries Ltd (ABL), this paper sought to broadly analyze the effectiveness of Corporate Social Responsibility on Brand Marketing with emphasis on the use of Aaker Brand Equity and Daisy Wheel Models. Specifically, the study aimed at identifying the factors that influence involvement in CSR activities by corporations; and the influence CSR grants have on the public perception and brand marketing. The study employed primary data and secondary data sources. Purposive sampling technique was used to select 20 senior/middle staff and 40 customers of ABL. The findings revealed that, CSR programmes are community-focus initiatives, involves programmes on education as well as health programmes in developing communities. The study therefore concluded that, CSR activities go a long way to build a solid brand identity and equity as in the case of ABL. It is therefore recommended that CSR initiative should engage all stakeholders who are mostly affected to help tailor CSR activities to solve societal needs.

A Numerical Simulation of UIC60 Rail-Weld's Fatigue and Crack Growth under Wheel Frictional Contact and Bending

In service condition rail joints, especially the weldments are under the action of various loadings which are not only working in multiple axis direction but also time-dependent having a cyclic and mixed-mode in nature and non-relative to each other. The surface of the rail and its weldment is acted by very high repetitive stress through the wheel and because of this contact stress the running surface or subsurface may have cracks or fractures due to fatigue. This work is based on numerical simulation of an aluminum thermite weldment on a UIC 60 rail under multi-axial fatigue crack propagation under the friction with surficial interaction between weldment and wheel with bending load due to vertically applied load through the wheel on the weld. Since contact is highly influenced by vertical load and also for minimizing the simulation time the lateral and longitudinal traction forces are not included in this study. The work formulation and discretization have been done with the finite element method and a non-linear lagrangian algorithm solver is applied. A 3-D rail-weld wheel model assembly and a semi-elliptical crack as a flaw on the weld surface are used to identify 3-Modes of SIFs along with its graphical plot generation. Simulation is performed under multi-axial weld wheel surface contact at different locations on weld running surface, taking into account varying position of fracture crack on weld 3-D model to calculate fracture life of weld joint and observation of fatigue crack propagation. This work involves the numerical and theoretical approach of fracture mechanics on created FE fatigue model using the Linear Elastic Fracture Mechanics (LEFM) method following Paris law for fracture mechanics. All the numerical simulation for critical fracture dimension and cycle count with stress intensity factor for weld failure data is estimated using software ANSYS 2020 academic and plotted, then comparison of predicted and observed transverse crack growth behavior and fatigue life of weld, based on Millions Gross Tonnes (MGT) is discussed.

Enhancing the tractive performance of unmanned vehicles using an optimised wheel-step driving system

A wheel-step driving system that can realise a wheel-step driving mode is proposed to improve the tractive performances of wheeled unmanned vehicles when driving on soft roads. Although the wheel-step driving system proposed in this paper adopts double wishbone suspension, it also can be applied for different suspension configurations after adjustment. In this paper, a typical sandy soil and a designated tyre are selected as hypotheses to verify the enhanced effect of wheel-step driving system on tractive performance. First, the wheel-soil interaction mechanism of the wheel-step driving mode is analysed based on terramechanics theory and the wheel-step driving strategy is optimised. The tractive performances of the wheel-step driving mode and the normal driving mode are compared and analysed through numerical calculations. Then, a soil model is established using discrete element software and a wheel model is established using dynamics software; the coupled simulation of the dynamic and discrete elements compares the drawbar pull, the driving torque and the sinkage in the normal driving mode, the wheel-step driving mode and the optimised wheel-step driving mode. The simulation data verify the effectiveness of the optimisation strategy used and the enhancement effect of the wheel-step driving mode on the traction performance. Finally, a soil-bin test system is built and a tractive performance experiment is performed. The experimental data and the simulation data show good agreement, thus verifying the correctness of the simulation model.

Event-based fast terminal sliding mode control design for a class of uncertain nonlinear systems with input delay: A quantized feedback control

This paper deals with the problem of regulation and tracking tasks for nonlinear dynamic systems that use a network medium to transmit state measurements. A novel quantized event-triggered fast terminal sliding mode controller (SMC) is proposed to reduce communication resources and computation loads while increase robustness against packet dropout, uncertainties, and disturbances. Then, new criteria are defined for the dynamic quantizer based on the event-triggering error, which increases the accuracy and facilitates the implementation procedures. In practice, delay-free systems are not realistic considerations, thus, their stability is analyzed in the presence of a dynamic quantizer and input delay under the proposed controller scheme. Then, the minimum inter-sampling time is derived, which guarantees the Zeno-free behavior and provides information about the cyber layer bandwidth in cyber-physical systems. Finally, three simulations on an unstable numerical model, the model of an inertia wheel inverted pendulum, and the mass-spring-damper model validate the effectiveness of the proposed methodology.

Modeling and Fatigue Characteristic Analysis of the Gear Flexspline of a Harmonic Reducer

The failure of harmonic gear drive is mainly caused by the fatigue fracture of flexible wheels and the fatigue damage of flexible bearings. In this paper, the stress sensitivity and fatigue life characteristics of flexible wheels with thin-walled vulnerable components are studied. Firstly, the structure of the flexible wheel of a B3-80 general harmonic gear reducer is designed, the finite element model of the flexible wheel is established by using ANSYS finite element software, and the finite element analysis results are compared with the theoretical calculations to verify the correctness of the model. Finally, by changing the cylinder length, smooth cylinder wall thickness and load, the maximum equivalent stress curves of the flexible gear ring, smooth cylinder and flexible wheel bottom are obtained, and the influence law of structural parameters on the stress characteristics of flexible wheel is obtained. At the same time, the influence laws of flexible wheel cylinder length and smooth cylinder wall thickness on the fatigue life of flexible wheel is studied, which provides a theoretical basis for the structural optimization design of the cup flexible wheel.

Numerical modeling of material removal mechanism and surface topography for gear profile grinding

Gear profile grinding is more complex than surface grinding owing to the specific shape of the grinding wheel and geometric characteristics of the gear tooth, resulting in difficulties in modeling grinding components. Consequently, conventional grinding models tend to fail. To address this issue, a novel semi-analytical modeling method of the material removal mechanism and surface generation for gear profile grinding is proposed. Firstly, the grinding wheel model is represented by a multi-information fusion matrix that contains kinds of information about grinding grits. Compared with the traditional models that require several matrices to represent respective information, the proposed wheel model incorporates multi-dimensional information without extending the original matrix size and data length, which is more efficient. Then, a numerical model for the grinding process is developed by analyzing grit kinematics and grit-workpiece contact to reveal the material removal mechanism, and it is found that the cross-section shape of 3D cutting chips changes in the direction of the contact line. Furthermore, a surface topography model is established considering the specific pile-up effect. In this process, based on the length conservation of the tooth profile curve after straightening, the body Boolean operation is replaced by matrix calculation which reduces the dimension of data from 3D to 2D. Thus, computing time is reduced greatly, and this method does not require knowledge of the generation mechanism for tooth profile. Finally, experiments are conducted and the effects of grinding parameters on surface topography are investigated. The experimental results match well with model predictions, proving the model is effective. This work provides further understanding of the material removal mechanism for gear profile grinding. Meanwhile, it can also be extended and applied to other grinding processes for workpieces with complex geometry.

Cornering stiffness characteristics of honeycomb wheels: A parametric analysis using response surface method

Non-pneumatic wheels with honeycomb spokes exhibit high out-of-plane rigidity and thereby high cornering stiffness with force saturation at very low side-slip deformations. In this study, three-dimensional finite element (FE) models of a honeycomb wheel with three different cell angles were developed to investigate its cornering stiffness characteristics. The validity of the developed models was demonstrated by comparing predicted wheel responses with the reported data under identical operating conditions. Regression models relating wheel cornering stiffness with the significant design parameters and their two-factor interactions were subsequently formulated using the results derived from the FE models based on the design points obtained using half fractional factorial and central composite design approaches. The regression models revealed relatively good prediction ability within the design space considered. It is shown that cornering stiffness of the honeycomb wheel is strongly influenced by the geometric and material properties of the annular layer and the tread, while the lateral stiffness is mostly affected by honeycomb spokes and tread design parameters. The regression models could thus serve as an efficient design tool to derive design guidance for honeycomb wheels for realizing desired cornering stiffness.

Damage and Fatigue Life Evaluation for Laser Cladding Remanufactured Wheel

Owing to high speeds and heavy loads, the wheels of trains and locomotives undergo gradual but significant damage. Conventionally, these damaged wheels are repaired using the rotatory repair method; however, this approach results in large amounts of material waste. To address this issue, in this study, laser cladding remanufacturing technology was employed to repair a damaged wheel. The contact stress and creep characteristics of the cladded wheel were determined using Simpack, a dynamic simulation software program. The existing damage function model, which is based on the wear number, was modified, and this modified model was used to perform damage assessments for the remanufactured wheel. Furthermore, a life evaluation model for wheels remanufactured using this laser cladding technology was established. The service life of the cladded wheel calculated using this model was in good agreement with the design life of the wheel.

РАЗРАБОТКА МИКРОГИДРОЭЛЕКТРОСТАНЦИЙ ДЛЯ МАЛЫХ РЕК ГОРНОЗАВОДСКОЙ ЗОНЫ ЧЕЛЯБИНСКОЙ ОБЛАСТИ

Small hydroelectric power generation is attractive from both an environmental and economic point of view. Technological innovations and mitigation measures are making small hydroelectric power plants an inexpensive and viable source of renewable energy which can be generated independently. They contribute not only to environmental protection, but also reduce human dependence on fossil fuels. This study is dedicated to finding solutions based on renewable energy source technologies and innovations using the example of the Chelyabinsk region. The experimental model of a micro-hydroelectric power station water wheel presented in this article, and the studies carried out on the basis of this model were used to carry out preliminary calculations. As a result, we found that such micro-hydroelectric power plants are capable of generating about 9–13 kW∙h, about 170–266 kW∙h/day and from 63 to 99 MW∙h/year.