Terramechanics is the broad study of terrain-vehicle systems. In this book, the complex physical processes associated with the static and dynamic interplay between (powered and towed) wheeled and tracked vehicles with natural and man-made surfaces are analyzed and mathematically modeled.The focus of the book is the technical or engineering problem of predicting the performance of a specific vehicle-terrain system - real or yet to be designed. Performance here includes such things as:- the generalized mobility of a specific vehicle over a given terrain- the trafficability of a terrain to the passage of various types and numbers of vehicles.- traction performance parameters such a tractor drawbar pull and bulldozer blade push- vehicle travel speeds and so onIn very logical and systematic manner, the book builds on the basic principles of engineering soil mechanics to develop progressively more complex mathematical models of the behavior of wheel-based vehicle systems. These ideas are then extended into the considerably more complex area of tracked vehicle systems.Much very recent research work has been used in the development of these models and extensive experimental and field research is used to validate them.The book synthesizes a large amount of very recent research work in this field into an integrated whole. Much of this work derives from specialist International Conferences and Proceedings whose contents are often very difficult to find.Specific and unique features of this book include:- a comprehensive treatment of pneumatic and flexible tired systems and- the presentation of a new method for predicting the performance of track type vehicles based on small scale machine model studies.- a trafficability of tired or tracked vehicles running on a weak soil or snow
Industry Reviews
This book is devoted to terramechanics (the physical mechanics of land locomotion, i.e. trafficability of wheeled and tracked vehicles running on soft terrains). The ability of a construction or agricultural machine to do effective work in the field depends on the properties of the terrain, and primarily upon the strength and deformation characteristics of soil, sand, loam, snow or other materials. The preceding books on terramechanics dealt, as a role, with empirical approach to the subject. The essence of this book is a synthesis of theoretical mechanics and experimental results. As a consequence, the land-locomotion mechanics may be regarded as a mathematical and mechanical branch of the science. The off-the-road trafficability and working capacity of a vehicle depends principally on ground properties. The importance of properly-conducted experiments to determine the soil-machine system constants, the significance of size effect, the problem of interaction between wheel, track belt and terrain, and the validity of simulation methods are underlined in this book. In Chapter 1 the authors consider some-experimental field procedures that may be carried out to determine the soil constants which determine the shear resistance deformation characteristics, as well as compression characteristics of the soil, including properties of snow or overconsolidated clays. The authors analyze the interface between two domains of machinery operation design and ground behavior. This allows the engineers to construct models of vehicle running behaviour and to perform terrain trafficability studies. Chapter 2 considers the land locomotion mechanics of vehicle systems with ridged wheel. This is the simplest machine-terrain interaction problem of predicting the loaded ridged cylindrical drum operation in a compressible and potentially yielding medium. The prediction is made by developing the mathematical models of the system. The authors model a number of different simple drum/terrain systems: a static loaded cylindrical drum operation on an elasto-plastic and/or visco-plastic medium; heavy cylindrical towed self-powered drums which drive or brake over hard, viscoelastic and/or sandy surfaces. Chapter 3 considers distribution flexible-tire wheel systems; the authors develop a theory to determine the relations between axial load, torque, and ground reaction and contact pressure distribution of the tire, taking into account the compression and shear deformation of soft terrain. Some important relationships between thrust or drag, land locomotion resistance, driving or breaking force and slip ratio have been established. The authors use a mix of empirical and analytical functions in tired-vehicle behaviour prediction. Chapter 4 presents terrain-track system constants for prediction of such machines like bulldozers, army tanks and snowmobiles. The measurements are performed for standard T-shaped track model plate, and are scaled up to real machinery sizes using the dimensional analysis and similarity. In Chapters 5 and 6, the land locomotion mechanics of a tracked vehicle equipped with ridged and flexible track belts are analyzed. The behaviour of simplest tracked vehicle systems of riged-track types and the performance of specific tracked vehicle with flexible track systems which requires to operate upon particular complex terrain are examined in a generic manner. The modeling is based on a mixture of experimentally found parameters and analytical considerations. This book synthesizes an important practical information for the prediction of pneumatic and flexible tire systems, the performance of track type vehicles, and trafficability of tire or tracked vehicles running on a weak soil or snow. This book may be very useful to students, postgraduate students, engineers and scientists who deal with terramechanics and off-the-road trafficability. Yurj N. Sankjn (Ul'yanovsk) Zentralblaatt Math 20C
