Frictional Impact Analysis Of Constrained Multibody Mechanical Systems

This volume constitutes an advanced introduction to the field of analysis, modeling and numerical simulation of rigid body mechanical systems with unilateral constraints. The topics include Moreau's sweeping process, the numerical analysis of nonsmooth multibody systems with friction, the study of energetical restitution coefficients for elasto-plastic models, the study of stability and bifurcation in systems with impacts, and the development of a multiple impact rule for Newton's cradle and the simple rocking model. Combining pedagogical aspects with innovative approaches, this book will not only be of interest to researchers working actively in the field, but also to graduate students wishing to get acquainted with this field of research through lectures written at a level also accessible to nonspecialists.

This book presents suitable methodologies for the dynamic analysis of multibody mechanical systems with joints. It contains studies and case studies of real and imperfect joints. The book is intended for researchers, engineers, and graduate students in applied and computational mechanics.

This book analyzes several compliant contact force models within the context of multibody dynamics, while also revisiting the main issues associated with fundamental contact mechanics. In particular, it presents various contact force models, from linear to nonlinear, from purely elastic to dissipative, and describes their parameters. Addressing the different numerical methods and algorithms for contact problems in multibody systems, the book describes the gross motion of multibody systems by using a two-dimensional formulation based on the absolute coordinates and employs different contact models to represent contact-impact events. Results for selected planar multibody mechanical systems are presented and utilized to discuss the main assumptions and procedures adopted throughout this work. The material provided here indicates that the prediction of the dynamic behavior of mechanical systems involving contact-impact strongly depends on the choice of contact force model. In short, the book provides a comprehensive resource for the multibody dynamics community and beyond on modeling contact forces and the dynamics of mechanical systems undergoing contact-impact events.

While the stability theory for systems with bilateral constraints is a well-established field, this monograph represents a systematic study of mechanical systems with unilateral constraints, such as unilateral contact, impact and friction. Such unilateral constraints give rise to non-smooth dynamical models for which stability theory is developed in this work. The book will be of interest to those working in the field of non-smooth mechanics and dynamics.

This book deals with the dynamics of mechanical systems in presence of impact and friction. The contributors are an international group of engineers and scientists from industrial and academic institutions of more than 23 countries around the world concerned with the modeling, analysis, measurement and control of nonsmooth mechanical structures. Contact laws lead to mathematical models that are highly nonlinear and nonsmooth or discontinuous. Discontinuous and nonsmooth processes introduce problems with data processing techniques and analytical methods. Thanks to great advances in computer technology and computational analysis, as well as the introduction of new experimental devices such as the atomic-force microscope and the quartz-crystal-microbalance probe, the study of impact and friction ? one of the oldest problems in physics, is now in a phase of rapid and exciting development. The growing number of research breakthroughs have promoted the development of new technologies in the description and design of systems with impact and friction models to understand nature, structures, machines, transportation systems, and other processes. A fairly comprehensive picture of these new developments is presented in this book by researchers who are giving up-to-date accounts of the present state of the field in many aspects.The book is essential for introducing readers in mechanical engineering, material science, applied mathematics, aerospace engineering, ocean engineering, biomechanics, and civil engineering to recent developments in nonsmooth mechanics. It is also useful for self-study purposes by professionals and practitioners in the field.

As mechanical systems become more complex so do the mathematical models and simulations used to describe the interactions of their parts. One area of multibody theory that has received a great deal of attention in recent years is the dynamics of multiple contact situations occurring in continuous joints and couplings. Despite the rapid gains in our understanding of what occurs when continuous joints and couplings interact, until now there were no books devoted exclusively to this intriguing phenomenon. Focusing on the concerns of practicing engineers, Multibody Dynamics with Unilateral Contacts presents all theoretical and applied aspects of this subject relevant to a practical understanding of multiple unilateral contact situations in multibody mechanical systems. In Part 1, Professor Pfeiffer and Dr. Glocker provide an exhaustive review of the laws and principles governing the dynamics of unilateral contacts in multibody mechanical and technical systems. Among the topics covered are multibody and contact kinematics, the dynamics of rigid body systems, multiple contact configurations, detachment and stick-slip transitions, frictionless impacts, impacts with friction, and the Corner law of contact dynamics. In Part 2, the authors present numerous applications of the theories presented in Part 1. Each chapter in this part is devoted to a different law, theory, or model, such as discontinuous force laws, classical impact theory, Coulomb's friction law, and mechanical and mathematical models of impacts and friction. In addition, each chapter features several practical examples that allow engineers to observe the concepts described in action. Examples are drawn from a broad array of fields and range from hammering in gears as occurring in a synchronous generator to impacts and friction as observed in a child's woodpecker toy, from a demonstration of classical impact theory using an automobile gear box example, to Coulomb's friction law as applied to a turbine blade damper. Multibody Dynamics with Unilateral Contacts is an indispensable resource for mechanical engineers working on all types of multibody systems and the friction and vibration problems that can occur in them. It is also a valuable reference for researchers studying nonlinear dynamics. The only book devoted entirely to the theory and applications of onE of the most crucial aspects of multibody system design. This is the first book to focus exclusively on the theory and applications of multiple contact situations occurring in continuous joints and couplings in multibody systems. As such, it is a valuable resource for engineers working on mechanical systems with interrelated multiple parts. Multibody Dynamics with Unilateral Contacts * Provides a comprehensive examination of the laws and principles governing the dynamics of unilateral contacts in multibody mechanical and technical systems. * Presents the latest mathematical models and simulation techniques for describing the interactions of joints and couplings in multibody systems. * Describes practical applications for all the concepts covered. * Includes numerous examples drawn from a wide range of fascinating and enlightening real-world demonstrations, including everything from an airplane's landing gear to a child's toy.

While the stability theory for systems with bilateral constraints is a well-established field, this monograph represents a systematic study of mechanical systems with unilateral constraints, such as unilateral contact, impact and friction. Such unilateral constraints give rise to non-smooth dynamical models for which stability theory is developed in this work. The book will be of interest to those working in the field of non-smooth mechanics and dynamics.

This volume contains the edited version of selected papers presented at the Nato Advanced Study Institute on "Computer Aided Analysis of Rigid and Flexible Mechanical Systems", held in Portugal, from the 27 June to 9 July, 1994. The present volume can be viewed as a natural extension of the material addressed in the Institute which was published by KLUWER in the NATO ASI Series, Vol. 268, in 1994. The requirements for accurate and efficient analysis tools for design of large and lightweight mechanical systems has driven a strong interest in the challenging problem of multibody dynamics. The development of new analysis and design formulations for multi body systems has been more recently motivated with the need to include general features such as: real-time simulation capabilities, active control of machine flexibilities and advanced numerical methods related to time integration of the dynamic systems equations. In addition to the presentation of some basic formulations and methodologies in dynamics of multibody systems, including computational aspects, major applications of developments to date are presented herein. The scope of applications is extended to vehicle dynamics, aerospace technology, robotics, mechanisms design, intermittent motion and crashworthiness analysis. Several of these applications are explored by many contributors with a constant objective to pace development and improve the dynamic performance of mechanical systems avoiding different mechanical limitations and difficult functional requirements, such as, for example, accurate positioning of manipulators.

A systematic treatment of current crashworthiness practice in the automotive, railroad and aircraft industries. Structural, exterior and interior design, occupant biomechanics, seat and restraint systems are dealt with, taking account of statistical data, current regulations and state-of-the-art design tool capabilities. Occupant kinematics and biomechanics are reviewed, leading to a basic understanding of human tolerance to impact and of the use of anthropometric test dummies and mathematical modelling techniques. Different types of restraining systems are described in terms of impact biomechanics. The material and structural behaviour of vehicle components is discussed in relation to crash testing. A variety of commonly used techniques for simulating occupants and structures are presented, in particular the use of multibody dynamics, finite element methods and simplified macro-elements, in the context of design tools of increasing complexity, which can be used to model both vehicles and occupants. Audience: An excellent reference for researchers, engineers, students and all other professionals involved in crashworthiness work.