Scientific and Technical Aerospace Reports


Book Description

Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.




Crashworthiness of Transportation Systems: Structural Impact and Occupant Protection


Book Description

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.




Impacts in Mechanical Systems


Book Description

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.




IUTAM Symposium on Unilateral Multibody Contacts


Book Description

Multibody dynamics started with the ideas of Jacob and Daniel Bernoul li and later on with d'Alembert's principle. In establishing a solution for the problem of the center of oscillation for a two-mass-pendulum Jacob Ber noulli spoke about balancing the profit-and-Ioss account with respect to the motion of the two masses. Daniel Bernoulli extended these ideas to a chain pendulum and called forces not contributing to the motion "lost forces", thus being already very close to d'Alembert's principle. D'Alembert considered a "system of bodies, which are interconnected in some arbitrary way. " He suggested separating the motion into two parts, one moving, the other being at rest. In modern terms, or at least in terms being applied in engineering mechanics, this means that the forces acting on a system of bodies are split into active and passive forces. Active forces generate motion, passive forces do not; they are a result of constraints. This interpretation of d'Alembert's principle is due to Lagrange and up to now has been the basis of multi body dynamics (D' Alembert, Traite de Dynamique, 1743; Lagrange, Mecanique Analytique, 1811). Thus, multibody dynamics started in France. During the nineteenth century there were few activities in the multi body field even though industry offered plenty of possible applications and famous re presentatives of mechanics were aware of the problems related to multibody dynamics. Poisson in his "Traite de Mecanique" (Paris 1833) gave an im pressive description of these problems, including impacts and friction.




Contact Force Models for Multibody Dynamics


Book Description

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.




Hybrid Systems: Computation and Control


Book Description

This book constitutes the refereed proceedings of the 10th International Conference on Hybrid Systems: Computation and Control, HSCC 2007, held in Pisa, Italy in April 2007. The 44 revised full papers and 39 revised short papers presented together with the abstracts of 3 keynote talks were carefully reviewed and selected from 167 submissions. Among the topics addressed are models of heterogeneous systems, computability and complexity issues, real-time computing and control, embedded and resource-aware control, control and estimation over wireless networks, tools for analysis, verification, control, and design, programming languages support and implementation, applications, including automotive, communication networks, avionics, energy systems, transportation networks, biology and other sciences, manufacturing, and robotics.




New Trends in Mechanism and Machine Science


Book Description

This book contains the papers of the European Conference on Mechanisms Science (EUCOMES 2012 Conference). The book presents the most recent research developments in the mechanism and machine science field and their applications. Topics addressed are theoretical kinematics, computational kinematics, mechanism design, experimental mechanics, mechanics of robots, dynamics of machinery, dynamics of multi-body systems, control issues of mechanical systems, mechanisms for biomechanics, novel designs, mechanical transmissions, linkages and manipulators, micro-mechanisms, teaching methods, history of mechanism science and industrial and non-industrial applications. This volume will also serve as an interesting reference for the European activity in the fields of Mechanism and Machine Science as well as a source of inspirations for future works and developments.




Multibody Mechatronic Systems


Book Description

This book gathers the latest advances, innovations, and applications in the field of multibody and mechatronic systems. Topics addressed include the analysis and synthesis of mechanisms; modelling and simulation of multibody systems; railway and vehicle dynamics; mechatronic systems for energy harvesting; robot design and optimization; and mechatronic design. It gathers the second volume of the proceedings of the 7th International Symposium on Multibody Systems and Mechatronics (MuSMe), virtually held in Cordoba, Argentina, on October 12-15, 2021, within the framework of the FEIbIM Commission for Robotics and Mechanisms and IFToMM Technical Committees for Multibody Dynamics and for Robotics and Mechatronics.




New Trends in Mechanism and Machine Science


Book Description

This work presents the most recent research in the mechanism and machine science field and its applications. The topics covered include: theoretical kinematics, computational kinematics, mechanism design, experimental mechanics, mechanics of robots, dynamics of machinery, dynamics of multi-body systems, control issues of mechanical systems, mechanisms for biomechanics, novel designs, mechanical transmissions, linkages and manipulators, micro-mechanisms, teaching methods, history of mechanism science and industrial and non-industrial applications. This volume consists of the Proceedings of the 5th European Conference on Mechanisms Science (EUCOMES) that was held in Guimarães, Portugal, from September 16 – 20, 2014. The EUCOMES is the main forum for the European community working in Mechanisms and Machine Science.