Showing papers in "Vehicle System Dynamics in 1981"
TL;DR: In this paper, the effects of lateral front fork flexibility on the vibrational modes of single-track vehicles have been studied by means of a mathematical model and the results of the analysis have been translated into practical advice for a more optimal front fork construction.
Abstract: SUMMARY By means of a mathematical model the effects of lateral front fork flexibility on the vibrational modes of single-track vehicles have been studied. The analysis performed by Sharp has been used as a starting point. The results have been compared with Roe's empirical findings. The results of the analysis have been translated into practical advice for a more optimal front fork construction.
68 citations
TL;DR: In this article, the Mechanics of Automotive Hydraulic Dampers at High Stroking Frequencies are discussed. But they do not consider the effect of high-stroking frequency on vehicle system dynamics.
Abstract: (1981). The Mechanics of Automotive Hydraulic Dampers at High Stroking Frequencies. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 82-85.
63 citations
TL;DR: In this paper, the authors reviewed recent developments in off-road vehicle dynamics and applied new techniques to the particular problems associated with offroad operation tend to lag behind practices established for road vehicles.
Abstract: SUMMARY Recent developments in off-road vehicle dynamics are reviewed. Progress on this topic and the application of new techniques to the particular problemsassociated with off-road operation tend to lag behind practices established for road vehicles. The factor which limits further progress is the lack ofappropriate off-road tyre data, in particular, on vibrational and lateral force generation characteristics. Also, a long term study should be aimed at understanding the dynamic behaviour of tyres on yielding surfaces.
53 citations
TL;DR: In this article, a survey of the developments where tire mass plays an important role is given, where the frequency of the imposed oscillations is assumed to be below ca. 40 Hz and the underlying theoretical considerations concerning the massless tire have been discussed.
Abstract: SUMMARY During the last decade research has been conducted on the dvnamics of the tvre considered as a vehiclecomponent. Asurvey is given of these developments where tyre mass plays an important role. The underlying theoretical considerations concerning the massless tyre have been discussed as well. Two groups of tyre response have been distinguished: the lateral (out-of-plane) response and the vertical/longitudinal (in-plane) response to motions of the wheel. In both categories tyre compliance, slip and inertia have influence. The dynamic properties of the rolling tyre have been presented in the form of transfer functions and/or differential equations. The frequency of the imposed oscillations is assumed to be below ca. 40 Hz. Non-linear effects and modelling have been briefly touched on.
47 citations
TL;DR: In this article, the state-of-the-art of active suspensions for railway vehicles is reviewed, both vertical and lateral, and the primary focus is on ride quality control.
Abstract: SUMMARY This paper reviews the state-of-the-art of active suspensions for use on railway vehicles. The primary focus of the paper is on ride quality control, both vertical and lateral, and on lateral stability control. The section on theoretical considerations summarizes the results of a one-degree of freedom optimization and then investigates analytically the use of active suspensions for lateral ride and stability augmentation. It is shown that separate control structures using different measurements and actuator actions are very effective in controlling both ride quality and stability. A section on a survey ofcurrent activities reviews published research on active railway suspension work around the world. Finally a concluding section indicates future trends in active suspension applications.
44 citations
TL;DR: In this article, a forced steering rail vehicle employs linkages between the carbody and wheelsets to force a more radial wheelset alignment, and the curve negotiation capability of forced steering trucks is significantly improved over conventional and self-steered radial trucks.
Abstract: SUMMARY A forced steering rail vehicle employs linkages between.the carbody and wheelsets to force a more radial wheelset alignment. It is shown that the curve negotiation capability of forced steering trucks is significantly improved over conventional and self steering radial trucks. Parametric curves are presented showing angle-of-attack and lateral flange force as a function of steering gain parameters and truck bending stiffness. It is also shown that the forced steering concept can produce kinematic instability and severely reduced critical speeds for low conicities and creep coefficients. Analytic expressions are derived that illustrate how these kinematic instabilities can be avoided.
33 citations
TL;DR: In this article, the effect of suspension system nonlinearities on heavy truck vibration was investigated and the effects of nonlinearity on heavy vehicle system dynamics were discussed, and the results showed that suspension system nonslinearity has a significant impact on the performance of heavy vehicle vibration.
Abstract: (1981). The Effect of Suspension System Nonlinearities on Heavy Truck Vibration. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 97-102.
29 citations
TL;DR: In this article, the authors compare the mechanical properties of cars and trucks with comparable properties of the motor car to explain why the motor truck and tractor-trailer can exhibit fixed-control instability at moderate levels of lateral acceleration.
Abstract: SUMMARY The mechanical properties of tires and trucks are contrasted with comparable properties of the motor car to explain why the motor truck and the tractor-trailer can exhibit fixed-control instability at moderate levels of lateral acceleration. The (1) rearward bias in the distribution of roll stiffness, (2) large ratio of e.g. height to track, and (3) low torsional stiffness of the parallel-rail frame (as typically employed in heavy commercial vehicles) are found to be the major factors implicated in this phenomenon. Experimental and analytical evidence is provided to show how tire inflation pressure and mixes of (a) tire-carcass construction and (b) tread design also influence stability at moderate levels of lateral acceleration. Conclusions relating to the safety of commercial vehicle operations are drawn.
26 citations
TL;DR: In this article, the state-of-the-art in analysing a number of ground manoeuvring processes on aircraft is described and the mathematical models are as good as the data supplied to them.
Abstract: SUMMARY The state-of-the-art in analysing a number of ground manoeuvring processes on aircraft is described. The mathematical models are as good as the data supplied to them.
25 citations
22 citations
TL;DR: In this paper, the technical state-of-the-art of ground transportation vehicles interacting with flexible, perturbed guideway systems is reviewed with emphasis on high-speed passenger-carrying systems.
Abstract: SUMMARY The technical state-of-the-art of ground transportation vehicles interacting with flexible, perturbed guideway systems is reviewed with emphasis on high-speed passenger-carrying systems Currently available modelling, analysis, and simulation techniques as well as parametric results illustrating the dominant interaction dynamics are summarized Experimental studies and correlations of field data with analytical results are described and areas in which further research is required are identified
TL;DR: In this article, the prediction of the dynamic response of vehicles to lateral track irregularities is presented. But the prediction is limited to the case of a single vehicle and does not cover all vehicles.
Abstract: (1981). Prediction of the Dynamic Response of Vehicles to Lateral Track Irregularities. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 106-109.
TL;DR: In this paper, a study of the Directional and Roll Dynamics of Multiple-Articulated Vehicles (MADV) is presented. Butts et al. present a different approach to the same problem.
Abstract: (1981). A Study of the Directional and Roll Dynamics of Multiple-Articulated Vehicles. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 74-77.
TL;DR: In this paper, a study of the Yaw Stability of Tractor-Semitrailer Combinations is presented, with a focus on the YAW stability of TSCs.
Abstract: (1981). A Study of the Yaw Stability of Tractor-Semitrailer Combinations. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 102-106.
TL;DR: In this article, the effects of suspension friction on vehicle riding comfort were investigated and the effect of suspension friction on vehicle ride comfort was discussed. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 85-91.
Abstract: (1981). Effects of Suspension Friction on Vehicle Riding Comfort. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 85-91.
TL;DR: In this paper, the self-excited vibrations of truck Tandem Axle Suspension and Transmission Systems were investigated. But the authors focused on the selfexcited Vibrations of the transmission and not the suspension.
Abstract: (1981). Self-excited Vibrations of Truck Tandem Axle Suspension and Transmission Systems. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 201-202.
TL;DR: In this paper, the roll stability during steady-state cornering of two-axle, articulated vehicles is investigated and the motion is described by eight coupled equations of motion, whose derivation is explained.
Abstract: The roll stability during steady-state cornering of frame-steered two-axle, articulated vehicles is considered. The motion is described by eight coupled equations of motion, whose derivation is explained. These equations are solved numerically for typical design data and the effect on stability of changing different design parameters is explored. Provided that the longitudinal positions of the centres of gravity of the front and rear sections of the vehicle are kept close to the positions of the front and rear axles respectively, good stability can be achieved, comparable to that for a rigid vehicle. For the covering abstract of the conference see TRIS 378303. (Author/TRRL)
TL;DR: In this paper, generic properties and performance characteristics of passenger rail vehicles are described and compared. But the authors do not discuss the performance of the trains themselves, and do not consider the locomotive.
Abstract: (1981). Generic Properties and Performance Characteristics of Passenger Rail Vehicles. Vehicle System Dynamics: Vol. 10, No. 2-3, pp. 119-122.
TL;DR: In this article, the relationship between handling characteristics and vehicle design parameters is analyzed using a simple vehicle model and the results of closed-loop tests show the adaptability of drivers to the dynamic characteristics of vehicles.
Abstract: SUMMARY Vehicle Handling Characteristics and Their Relationship to Vehicle Design Parameters This paper reviews currently used test procedures for the determination of vehicle handling characteristics in the time and frequency domain. Driver subjective opinions lead to preferred tendencies or ranges of these quantities. The results of closed-loop tests show the adaptability of drivers to the dynamic characteristics of vehicles. The relationship between handling characteristics and design parameters is obtained from the analysis of a simple vehicle model. Comparison of these results with the prefered ranges found in closed-loop tests yields aids for the design of vehicles.
TL;DR: A comparative study of four different test procedures for quantifying the transient lateral response of automobiles is presented in this article, where the random steering technique appears to offer several advantages over other procedures in terms of space-requirement and the amount of transient dynamics information generated.
Abstract: SUMMARY A comparative study of four different test procedures for quantifying the transient lateral response of automobiles is presented in this paper Both full-scale testing and analysis have been used in this study The random steering technique appears to offer several advantages over other procedures in terms of space-requirement and the amount of transient dynamics information generated, whereas the step-steering procedure is more suited to the measurement of steady-state behavior of the automobile