Wheel Force Research Articles

Predicting wheel forces using bearing capacity theory for general planar loads

This paper assesses the applicability of bearing capacity theory for evaluating the forces generated on wheels operating on clay under steady rolling conditions. Considering advances in bearing capacity theory, in particular the interaction diagrams developed for general loading, a theoretical model for computing the horizontal force or torque from fundamental input parameters such as the vertical force (weight), wheel diameter, and undrained shear strength of the soil is presented. The predictions are compared with existing analytical solutions and data from laboratory testing, and reasonable agreement is demonstrated. The newly proposed model provides a means to predict wheel forces analytically under any operating condition (driven, braked, or towed), provided the contact length and so-called contact angle, which defines the position of the contact interface, can be estimated. The model provides a rigorous, convenient framework for evaluating wheel forces under arbitrary loading and enables a natural physical interpretation of the mobility problem.

On Optimizing Steering Performance of Multi-axle Vehicle Based on Driving Force Control

The steering performance of multi-axle vehicle with independent driving system is affected by the distribution of the wheel driving force. A nonlinear vehicle dynamics model including magic formula tire model for describing 11 DoF four-axle vehicle with dual-front-axle-steering (DFAS) system was presented. The influence of different driving force distribution scheme on the steering performance of the vehicle was analyzed. A control strategy for improving the steady response and transient response of the vehicle steering is proposed. The results show: For the steady response, setting different drive force for internal and external wheels according to the actual steering characteristics of the vehicle can effectively improve its steering characteristics; For the transient response, adopting the zero sideslip angle control strategy and using the PID control algorithm to control the driving force of the outside wheel of tear-two-axle, under angle step input, the vehicle sideslip angle can quickly stabilize to 0 and yaw rate also significantly decreases.

System for measurement of interaction forces between wheel and rail for railway vehicles

Determination of the interaction forces between wheel and rail of railway vehicles is essential for assessment of the vehicle dynamic characteristics from point of view of running safety and rail loading as well as for approval the vehicle and alignment them to the Technical Specification for Interoperability. The direct measurement of transverse and vertical interaction forces using the existing full-disk wheel is practical impossible due to the impossibility of separating the two types of forces. To avoid this impediment it was realized a measuring wheelset fitted with 12 spokes achieved as force transducers for measurement of the vertical forces and 12 spokes achieved as force transducers for measurement of the transverse forces. The measuring wheelset was calibrated as a force transducer and was used to determine the wheel and rail interaction forces for LE-MA 6000kW electric locomotive made by Softronic Craiova. The article presents the measuring wheelset, the calibration principle and the calibration characteristics as well as some time history of the main parameters which characterize the running safety and rail loading, determined in the on-track tests.

Development of a finite element simulation model for new continuous measuring method of wheel and rail contact force in railway vehicle

Development of a finite element simulation model for new continuous measuring method of wheel and rail contact force in railway vehicle

Analysis of Vehicle-Force-Induced Dynamic Pore Pressure in Saturated Pavement With LSPM Drainage Base

Abstract Dynamic pore pressure caused by moving-vehicle forces may cause damage in asphalt pavement. However, few field data of dynamic pore pressure are available. This research aimed to study the time histories of dynamic stress and dynamic pore pressure in the drainage base of large stone porous asphalt mixes (LSPM) under moving-vehicle forces. To this end, heat-resistant dynamic stress and pore-pressure sensors were developed and used to measure the dynamic stresses and pore pressures in the field. A numerical fluid-solid coupling simulation method was used to analyze the response of pavement under moving wheel forces. Numerical simulation results matched well with in situ test data. The time histories of dynamic pore pressure in the pavement are quantitatively analyzed, and the hydraulic mechanism of moisture-induced damage is verified. This study provides a theoretical guide for pavement design.

Predicting wheel forces using bearing capacity theory for general planar loads

Predicting wheel forces using bearing capacity theory for general planar loads

Intelligent Tires?A Review of Tire Characterization Literature

In this article, previous literature on the intelligent tire has been reviewed, especially focusing on the estimation of tire characteristics such as tire forces and contact patch characteristics of a loaded rolling tire. The contact patch features and the global deformation of tire are identified as the key factors for the tire force estimation. In this review article, the measurement values to characterize these estimation parameters and the corresponding sensors are investigated. The estimated tire features and associated algorithms are presented based on the type of measurements. It is revealed that numerous dynamic features including wheel forces, slippage in contact, contact length on dry and wet roads, and hydroplaning can be identified by using the intelligent tire system. From this review, the authors of this article suggest that intelligent tire can be exploited to analyze the tire characteristics themselves besides the application for the advanced vehicle control. However, for the purpose of tire characteristic analysis, the well-established physical concepts must be employed into the estimation process. This review article is expected to provide resources to researchers or developers who are interested in the advanced vehicle controls integrated with intelligent tire system, and who want to utilize the intelligent tire for the purpose of tire performance analysis as well.

Simulation Analysis of the Effects of a Rail Vehicle Running with Wheel Flat

This contribution deals with the computer simulation and the follow analysis of the rail vehicle running with wheel flat. It comprises of two parts. The first part addresses to the problem of rail vehicle operational, which wheel is damaged. There are several types of wheel damages. In this work the wheel flat problem is introduced. Generally, the rail vehicle running with wheel flat is adverse because the track can be shopworn, some parts of rail vehicle can be damaged and also operational condition for passenger or goods (depending on kind of rail vehicle) can be worse markedly. There is also included a system of forces and accelerations measurement during rail vehicle running on the given track section. The second part includes computer modelling and simulation of this phenomenon. Analyses were focused on the assessemnt of the rail vehicle motion smoothness and its damaging impact on the track. For this, there was created computer model of a twin-bogies passenger car, which the one wheel was modelled as damaged, i.e. wheel flat. Then, there were performed simulations of the rail vehicle running at various speeds. The passenger car was run on the straight track without irregularities in order to avoid adding excitation. Subsequently, values of the vertical wheel forces of the wheel with flat was evaluated.

The Analysis of a Rail Vehicle with a Tilting Bogie

The paper deals with simulation analysis of a rail vehicle with a tilting bogie. The goal is to determine the wheel force in the rail-wheel contact and subsequently determine the safety against derailment. The rail vehicle model was designed in CAD program CATIA and imported to program SIMPACK with the RAIL module extension afterwards. Eight variants of different velocity, vehicle occupancy and setting of the tilting mechanism were analysed. The vehicle model was run along a track composed of straight sections and four succesive curves. Diagrams of the examined quantities icluding the lateral flanging force, vertical wheel load and the safety against derailment for the eight different variants make the result of the simulation analysis. Arising from the analysis, the biggest differences of results can be seen between the two variants of the highest speed but with different occupancy.

Relationship between linear velocity and tangential push force while turning to change the direction of the manual wheelchair.

Wheelchair propulsion is a major cause of upper limb pain and injuries for manual wheelchair users with spinal cord injuries (SCIs). Few studies have investigated wheelchair turning biomechanics on natural ground surfaces. The purpose of this study was to investigate the relationship between tangential push force and linear velocity of the wheelchair during the turning portions of propulsion. Using an instrumented handrim, velocity and push force data were recorded for 25 subjects while they propel their own wheelchairs on a concrete floor along a figure-eight-shaped course at a maximum velocity. The braking force (1.03 N) of the inside wheel while turning was the largest of all other push forces (p<0.05). Larger changes in squared velocity while turning were significantly correlated with higher propulsive and braking forces used at the pre-turning, turning, and post-turning phases (p<0.05). Subjects with less change of velocity while turning needed less braking force to maneuver themselves successfully and safely around the turns. Considering the magnitude and direction of tangential force applied to the wheel, it seems that there are higher risks of injury and instability for upper limb joints when braking the inside wheel to turn. The results provide insight into wheelchair setup and mobility skills training for wheelchair users.

Custom Design Multi-Axial Engine Mount Load-Cell Development for Road Load Identification and Fatigue Life Estimation

Copyright © 2016 SAE International. Internal combustion engines are attached on the vehicle body using engine mounts composed of two cast iron brackets and a rubber isolator connecting them. Engine mount road load identification during vehicle durability tests on proving ground is a critical task for engine mount development. Using standard multi-axial load-cell is not possible unless major design revisions on the vehicle body or engine block are done. Using wheel force transducers and vehicle dynamic simulation tools need extensive model tuning work to get accurate load information. Hence, a custom multi-axial load-cell design is preferred for the engine mount load identification of a BCar I4 engine. The developed load-cell engine mount bracket can be installed without doing any design changes on the vehicle. Design, durability analysis, instrumentation, calibration and vehicle installation of custom designed six degree of freedom multi-axial load cell have been performed. Strain and acceleration measurements have been conducted on vehicle durability test track. Data have been processed to obtain forces and moments in six degree of freedom on the engine mounts. The loading information was used for fatigue life estimation.

차세대 고속철 주행속도를 대비한 교량받침의 장기마찰시험법

Structural behaviour of PSC box bridge, on which KTX train runs, is analysed up to 500 km/h speed considering 12 stages track irregularity and interaction between bridge and vehicle. To evaluate wheel forces and rotations of vehicle, lateral wheel forces, derail factor and offload factor calculated on the track combining the bridge and 170 m normal track are compared with existing allowed limits. Maximum longitudinal displacement and accumulated sliding distance of the brige bearings for simply supported and 2 span continuous PSC bridges are presented by each running speeds. Long-term friction tests based on EN-1337-2 are conducted between PTFE and DP-mate plates. Finally, the long-term friction tests are proposed to consider the increasing speed of next generation high-speed train.

An analytical mathematical method for calculation of the dynamic wheel–rail impact force caused by wheel flat

ABSTRACTThe simplified method to determine a vertical impact force of wheel with flat and rail interaction is presented in this article. The presented simplified method can be used to identify maximum contact force and its distribution in the contact length between the damaged wheel and the rail. The vertical impact force depends on geometrical parameters of the rail and wheel with flat, speed of vehicle and the angle of deviation of rail. This article demonstrates the influence of wheel with flat geometrical parameters, speed of vehicle to maximum contact force and its distribution in the contact zone. The obtained values of the simplified method for determination of a vertical contact force are compared with the results obtained from field measurements.

二次元重心位置制御が可能な車輪型ローバの不整地での走行性能の検討

A new type of rover which running on the rough terrain of a planet is investigated. The rover has a mechanism of active control of the gravity. Moments of load in two dimensional plates can control the vertical forces of wheels. A prototype of rover has been made and is intended. We study the forces of the wheels and calculate the load position for all same forces. For the prototype, the moment range is not enough for all same forces. However, examinations verify the active control of gravity is efficient for running rough terrain.

Grinding wheel motion, force, temperature, and material removal in rotational atherectomy of calcified plaque

Abstract This study investigates the grinding wheel motion, force, material removal, and temperature in rotational atherectomy (RA). RA utilizes a metal-bond diamond wheel to remove plaque from arteries to treat cardiovascular diseases. As a plaque surrogate, a bone workpiece was placed in a vessel simulator and subjected to RA with a wheel rotational speed of 160,000 rpm. This grinding process was monitored by a high-speed camera, a dynamometer, and embedded thermocouples. The results show this process has a 108 Hz wheel orbital frequency, an oscillating grinding force of 0.23 N, 90% debris smaller than 31 μm, and a 4.1 °C temperature rise.

鉄道台車のモーメントに着目した横圧推定式の検討

When railway vehicles pass through a sharp curve, yaw moment is generated at the bogie. This condition affects the increase of the lateral force of the outside wheel of the front axle of the leading bogie, which is important factor for assessing the running safety of railway vehicles. A Lateral-force/Wheel-load estimation equation has been developed as a method to calculate the lateral force and the wheel load during the curve passage of railway vehicles taking into account the yaw moment of the bogie. This equation is useful to estimate the risk of flange-climb derailment. The authors have newly suggested a more versatile Lateral-force/Wheel-load estimation equation with a focus on the improvement of the estimation of yaw moment of the bogie. Running tests using test track which has sharp curves were carried out to measure the generated forces of several components of the bogie, which are the sources of the yaw moment of the bogie. New equations were produced based on the test results, and compared with the measured lateral forces and wheel loads.

A hierarchical integrated chassis control strategy based on wheel force feedback

A hierarchical integrated chassis control strategy based on wheel force feedback

Investigation of Torsional Oscillations in Railway Vehicles

The development of semiconductor electro-technics during last decades allowed us to produce railway vehicles with very high tractive power. High performances reveal new problems that were unknown until these days. One of these problems are torsional oscillations of running wheelsets, which may appear and compromise the safety of railway vehicles. This article analyzes dynamical events that may occur in drives of the vehicles and that are bound with transmission of the torque to the wheels during the operation of the vehicle, which is exposed to the variable external influences (adhesion conditions, track irregularities, variation of wheel forces, etc.). This is based on the idea of a model of simplified drive of the real railway vehicle, which is used for simulation purposes. The model serves for the parametric analysis of individual components, to make an effective design or control remedy.

A hierarchical integrated chassis control strategy based on wheel force feedback

The motivation to investigate a novel integrated chassis control (ICC) strategy emerges from recent advances in on-board force transducers. This study proposes a novel hierarchical framework adopting feedback control on tyre force level, and an on-target high level control algorithm including Force Reference Generator and allocation strategy to supervise front steering and braking subsystems. In the proposed method, force reference is generated regarding linear vehicle behaviour and guaranteed to be achievable, bounded by tyre grip limit. Allocation strategy tracks force reference and penalises undesired vehicle body motion, capturing significantly faster dynamics. In order to address the non-linearities and uncertainties of the vehicle model, a modified model reference adaptive control (MRAC) scheme is used, which both stabilises the lateral dynamics and maintains maximum lateral performance. The proposed method is validated and evaluated on a multi-body vehicle model simulation.

Modelling and Simulations of Dynamics of the Low-Floor Tramcar with Independently Rotating Wheels

The article is devoted to the analysis of numerical simulation results of the tramcar dynamics. It presents the mathematical model of the one section of the low-floor tram with the bogie with independently rotating wheels. The simulations were performed according to different scenarios, connected with the track geometry, which seem to be dangerous for the tram behaviour e.g.: curving, gauge narrowing, track buckling, etc. Special attention was paid to wheel lateral displacement and forces occurring in wheel-rail contact. The simulation results reveal characteristic features of such an unconventional system of the tram, which can often demonstrate dynamics considered worse than in the conventional case of the tramcar.