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A series of computer simulation models for performance and design evaluation of tracked vehicles have emerged in the past decade. In contrast with empirical models developed earlier, they are based on detailed studies of the mechanics of vehicle-terrain interaction, and take into account all major vehicle design features and terrain characteristics. Thus, they provide a comprehensive and realistic tool for the vehicle engineer to optimize vehicle design and for the procurement manager to evaluate competing vehicle candidates. These models have been gaining increasingly wide acceptance in industry and governmental agencies. For instance, the model NTVPM for tracked vehicles with relatively short track pitch has been successfully used to assist vehicle manufacturers in the development of a new generation of high-mobility military vehicles and governmental agencies in the evaluation of vehicle candidates in Europe, North America and Asia.

This paper presents a series of simplified methods for analysing the steady-state steering response of various types of articulated vehicle including tractor-semitrailers, truck-full trailers, and the so-called “B-trains”. The effects on steering response of certain design parameters, tire cornering stiffness, and axle arrangements (tandem vs. single) are examined. Based on the analysis, a new parameter called “Tandem Axle Factor” is introduced to define the effects on the articulation angle of installing tandem axle in a trailer (or dolly). The prime objective of this paper is to provide vehicle designers and users with a convenient and simple means for evaluating the steering response of various types of articulated vehicle in steady-state turns, and with guiding principles for selecting an appropriate vehicle configuration and its design parameters from the directional stability standpoint.

This paper describes the results of a study of the steady-state steering response and directional stability of an articulated vehicle with a multi-axle forced steering dolly. The vehicle consists of a tractor and a multi-axle forced steering dolly, joined together through a long payload, such as pipes. Because of its unique design features, a new method of approach to the analysis of the steady-state directional behaviour of this type of vehicle has been developed. The effects of design and operational parameters of the vehicle on the tractor yaw rate, and on the curvature response and articulation angle response to steering input have been examined in detail.

In this paper, a digital computer model for studying the braking performance of an articulated vehicle equipped with anti-lock devices is presented. Using this computer model, the braking characteristics of a tractor-semitrailer fitted with a commercially available system (System A) is compared with that of the same vehicle equipped with a proposed system (system B). The deficiencies of system A are identified. The merits and disadvantages of system B are also examined. Based on the results of the simulation study, guiding principles for the development of the control logic of anti-lock brake systems are suggested.