Influence Of Wheels Research Articles

Wear Prediction of Curved Switch Rail in High-Speed Turnout and Influence of Wheel and Rail Wear on Vehicle Dynamic Performance

Wear Prediction of Curved Switch Rail in High-Speed Turnout and Influence of Wheel and Rail Wear on Vehicle Dynamic Performance

Drag reduction design and research of high-speed amphibious vehicle’s deformable track wheels

ABSTRACT In this study, the resistance characteristics of the amphibious vehicle in the transitional stage are studied. A deformable track wheel is designed and its effect on the amphibious vehicle’s resistance is studied. The numerical calculation method based on the RANS solver and the towing test method is used to analyse the hydrodynamic performance of the amphibious vehicle. Based on the comparison of the vehicle model with no wheel, the influence of wheels on additional resistance at the groove fault is studied. The inclination angles of the front and rear deformation wheels are studied respectively. The influence and principle of the track wheel configuration on drag are analysed and expounded in terms of pressure distribution, water climbing and spray on the wheel grooves, and the hull attitude. Finally, an adjustment strategy of the deformable configuration wheel in the transition stage is proposed.

Influence of wheel out‐of‐roundness on the remaining life of railway wheels under mixed‐mode fatigue loading

AbstractAs a common condition in train operation, the out‐of‐roundness (OOR) of wheels may have a great influence on the life of cracked wheels. In this study, the I–II mixed‐mode crack growth rate of different angles was tested, finite element analysis was carried out by using the test results, and the influence of different wheel roundness conditions on the life of cracked wheels was revealed. The results show that the mode II stress intensity factor of mixed‐mode cracks is the main driving force for crack propagation in the process of wheel rim crack growth. With an increase in the wheel scar length and the order of the wheel polygon, the crack propagation life decreases significantly.

Study on Aerodynamic Performance and Lightweight Multiobjective Optimization Design of Wheel With Entropy Weighted Grey Relational Analysis Methods

In order to improve the aerodynamic performance and optimization efficiency while wheel lightweight designing, a multi-objective optimization design method of wheel lightweight based on entropy weighted grey relational analysis (EGRA) was proposed in this article. The aerodynamic analysis finite element model of the assembled wheel was established, and the simulation accuracy was verified by experiments. Study the distribution law of performance parameters such as pressure and turbulent kinetic energy in flow field of the car, analyze the variation law of flow field velocity and turbulent intensity in front and rear wheel cavities of the assembled wheel, and analyze the cloud diagram distribution of temperature and surface convective heat transfer coefficient of the brake disc ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h_c</i> ). Research on the influence of wheels with different disc structures on the aerodynamic drag coefficient of the car ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C_d</i> ) and the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h_c</i> . Combined with grey relational analysis (GRA) and EGRA, the objective evaluation of the comprehensive aerodynamic performance of wheels with different disc structures was given. With the design of experiments (DOEs), 12 important design variables were screened out by contribution analysis method. Using the approximate model method, combined with the RBF surrogate model, a hybrid method combining EGRA and Non-Dominated Sorting Genetic Algorithm-II (NSGA- II) was proposed to lightweight and multi-objective optimize the assembled wheel. Comparing and analyzing the optimization platform recommending scheme, the technique for ordering preferences by similarity to ideal solution (TOPSIS) method preferring scheme and the EGRA method optimum scheme, it was found that the optimal compromise scheme was obtained by the EGRA method, the reduction of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C_d</i> was more obvious, and the improvement rates of performance were also more balanced. After multi-objective optimization, the mass of the assembled wheel was reduced by 10.83%, the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C_d</i> was reduced by 3.47%, and the average convective heat transfer coefficient of brake disc ( <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">h_a</i> ) was reduced by 8.02%. The optimized assembled wheel has a weight reduction of 32.74% compared with the same type of cast aluminum alloy wheel, which has a remarkable lightweight effect and significant reduction on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C_d</i> .

Approbation of an effective method for dynamic calculation of the steel and concrete bridge span

Problem statement. The article describes the method and results of determining the dynamic response of a continuous steel-reinforced concrete span of a road bridge to the passage of heavy vehicles, which is focused on the use of finite element computing systems. The data of dynamic calculations are compared with those obtained during full-scale dynamic tests of the operated structure. Results. Modern algorithms for dynamic calculation of continuous bridge structures on the action of sprung vehicles are analyzed, which allow taking into account the irregularities on the roadway, the influence of wheel bearing point movements on the vibrations of moving vehicles. It describes the sequence of performing dynamic calculations using modal analysis blocks and dynamic calculation of KE-complexes for a system of moving non-inert loads, followed by calculating the dynamic component of deflections and forces of elements of the bridge structure, taking into account the inertia of the vehicle and unevenness on the roadway. According modal analysis of steel-concrete span structures road bridge operated by means of spatial finite element calculation schemes are determined by their own shape supporting structure, which are then used for dynamic calculations in a moving inertial load. The results of dynamic calculations of the operated road bridge on the action of a three-axle truck moving at a constant speed are presented. Calculated deflections are compared with those obtained during full-scale static tests of the bridge. Numerical calculations estimate the effect of speed, roadway irregularities, and feedback between the vibrations of the bridge and the moving vehicle. Conclusion. The proposed method of dynamic calculation of bridge structures allows evaluating the dynamic quality of transport structures at the design stage and making optimal design decisions.

Influence of wheel and rail profile shape on the initiation of rolling contact fatigue cracks at high axle loads

ABSTRACTThe influence of wheel and rail profile shape features on the initiation of rolling contact fatigue (RCF) cracks is evaluated based on the results of multi-body vehicle dynamics simulations. The damage index and surface fatigue index are used as two damage parameters to assess the influence of the different features. The damage parameters showed good agreement to one another and to in-field observations. The wheel and rail profile shape features showed a correlation to the predicted RCF damage. The RCF damage proved to be most sensitive to the position of hollow wear and thus bogie tracking. RCF initiation and crack growth can be reduced by eliminating unwanted shape features through maintenance and design and by improving bogie tracking.

スポーツ用自転車における加速性能と各部品特性の関係

スポーツ用自転車における加速性能と各部品特性の関係

Indirect method for wheel–rail force measurement and derailment evaluation

Wheel set flange derailment criteria for railway vehicles are derived and the influence of wheel–rail contact parameters is studied. An indirect method for wheel–rail force measurement based on these derailment evaluation criteria is proposed. Laboratory tests for the calibration of strain–force devices on the bearing box are carried out to determine the relationship between the applied force and the measured strain. The simulation package, SIMPACK, is used to develop a passenger car model to generate wheel–rail forces and vibration signals. Different cases are considered in this model to provide an accurate validation of the identified wheel–rail forces. A feasibility test is conducted in the Beijing Loop test line using a passenger car equipped with a set of strain gauges on the wheel set. The comparison of the force time history applied to the instrumented wheel set and that obtained using the indirect method is presented.

An investigation on surface grinding of hardened stainless steel S34700 and aluminum alloy AA6061 using minimum quantity of lubrication (MQL) technique

In grinding process, the abrasives plunge and slide against the workpiece during material removal with high specific energy consumption and high grinding zone temperature. To improve process efficiency, lubrication becomes an important requirement of the grinding fluids, along with chip removal and cooling the grinding zone. Grinding fluids have negative influences on the working environment and machining cost in terms of the health of the machine operator, pollution, the possibility of explosion (for oil), filtering, and waste disposal. The use of minimum quantity of lubrication (MQL) with an extremely low consumption of lubricant has been reported as a technologically and environmentally feasible alternative to flood cooling. This paper deals with an investigation of the grindability of hardened stainless steel (UNS S34700) and aluminum alloy AA6061 using dry, MQL, and conventional fluid techniques. One type of SiC and five types of Al2O3 wheels (corundum) as well as vegetable and synthetic ester MQL oils have been tested. The influences of wheel and coolant–lubricant types have been studied on the basis of the grinding forces, surface topography, and surface temperature. Synthetic ester MQL oil was found to give better grinding performance than the vegetable MQL oils. It was argued that the improved performance of the ester oil is caused by the formation of tribo-films on the abrasives and the workpiece, which enhances lubrication by inhibiting metal–abrasive interaction. Also, the grindability of the machined specimens was found to increase substantially by using the MQL grinding process with soft and coarse wheels. In MQL grinding of AA6061 alloy, the use of vegetable oil resulted in the lowest surface roughness, whereas using synthetic ester additives lead to highest surface roughness because of higher chip loading on the grinding wheel and consequently more redeposited material on the workpiece surface.

The Influence of Wheel Rotating to FSAE Racing Car Aerodynamic Characteristics

In this paper, the numerical simulation analysis of jlu fsae racing car aerodynamic character based on star-ccm+ was introduced. Several simulated situations had been set and the results of the situations were compared. The effect of the wheel rotating situation of the racing car out flow and aerodynamic character was concluded. It was found that the air flows surrounding the wheels and the wings of the racing influenced each other. When the rotating wheel situation was set during the simulation, the effect that the air flows influenced could be simulated more clearly and the result could be more calculatedly. It was necessary to set the wheel rotate when to simulate the racing car aerodynamic character. From the simulated results, it also could be seen that it was also necessary to take care of the wheel rotate when to do the racing car wind tunnel test.

The generation of high-speed train noise from roughness

The forces generated in the contact area between railroad wheels and rails due to small scale roughness has been estimated using three analytical techniques: a simple average of the roughness, a point reacting spring model, and a full elastic interaction model. Roughness data measured in a number of parallel tracks in the rolling direction on partially worn wheels and rails was used in these three models. The forces estimated by all three analytical techniques were remarkably similar in the range of wavelengths important for noise generation from high-speed (200-to 400-km/h) trains. Wave-number decomposition of the roughness data has shown it to be bandlimited in the direction transverse to rolling, a result consistent with the similarity in the predictions of the three analytical techniques. The influence of wheel and rail profile and high roughness amplitudes at low wave number will be discussed.

Paper 1: The Dynamics of Railway Vehicles on Straight Track: Fundamental Considerations of Lateral Stability

The dynamics of existing railway vehicles on straight track is dominated by motions in the lateral plane commonly referred to as hunting. Hunting is a self-excited oscillation caused by the combined action of the conicity of the wheels and the creep forces acting in the contact plane between wheel and rail. In this paper existing and recently developed theories of the lateral motion of railway vehicles are discussed in relation to experimental work on both models and full-scale vehicles. It is shown that a realistic theory taking into account flexibility between the wheelsets and the frame in the longitudinal, lateral, and vertical directions, and the influence of wheel and rail profiles, yield values for the critical speeds which are consistent with experimental results. The influence of various parameters on stability is discussed and it is explained how railway vehicles can be designed for stable running at high speeds. Examples of suitable choices of suspension and other parameters will be given and experiments carried out in order to verify these concepts will be described.