This book is intended to help the reader understand impact phenomena as a focused application of diverse topics such as rigid body dynamics, structural dynamics, contact and continuum mechanics, shock and vibration, wave propagation and material modelling. It emphasizes the need for a proper assessment of sophisticated experimental/computational tools promoted widely in contemporary design. A unique feature of the book is its presentation of several examples and exercises to aid further understanding of the physics and mathematics of impact process from first principles, in a way that is simple to follow.
Studies of vibro-impact dynamics falls into three main categories: modeling, mapping and applications. This text covers the latest in those studies plus selected deterministic and stochastic applications. It includes a bibliography exceeding 1,100 references.
Fundamental guidance—including concepts, models, and methodology—for better understanding the dynamic behavior of materials and for designing for objects and structures under impact or intensive dynamic loading This book introduces readers to the dynamic response of structures with important emphasis on the material behavior under dynamic loadings. It utilizes theoretical modelling and analytical methods in order to provide readers with insight into the various phenomena. The content of the book is an introduction to the fundamental aspects, which underpin many important industrial areas. These areas include the safety of various transportation systems and a range of different structures when subjected to various impact and dynamic loadings, including terrorist attacks. Presented in three parts—Stress Waves in Solids, Dynamic Behaviors of Materials Under High Strain Rate, and Dynamic Response of Structures to Impact and Pulse Loading—Introduction to Impact Dynamics covers elastic waves, rate dependent behaviors of materials, effects of tensile force, inertial effects, and more. The book also features numerous case studies to aid in facilitating learning. The strength of the book is its clarity, balanced coverage, and practical examples, which allow students to learn the overall knowledge of impact dynamics in a limited time whilst directing them to explore more advanced technical knowledge and skills. Considers both the dynamic behavior of materials and stress waves, and the dynamic structural response and energy absorption, emphasizing the interaction between material behavior and the structural response Provides a comprehensive description of the phenomenon of impact of structures, containing both fundamental issues of wave propagation and constitutive relation of materials, and the dynamic response of structures under impact loads Based on the authors’ research and teaching experience as well as updated developments in the field Introduction to Impact Dynamics is the perfect textbook for graduate and postgraduate students, and will work as a reference for engineers in the fields of solid mechanics, automotive design, aerospace, mechanical, nuclear, marine, and defense.
Many physical systems require the description of mechanical interaction across interfaces if they are to be successfully analyzed. Examples in the engineered world range from the design of prosthetics in biomedical engi neering (e. g. , hip replacements); to characterization of the response and durability of head/disk interfaces in computer magnetic storage devices; to development of pneumatic tires with better handling characteristics and increased longevity in automotive engineering; to description of the adhe sion and/or relative slip between concrete and reinforcing steel in structural engineering. Such mechanical interactions, often called contact/impact in teractions, usually necessitate at minimum the determination of areas over which compressive pressures must act to prevent interpenetration of the mechanical entities involved. Depending on the application, frictional be havior, transient interaction of interfaces with their surroundings (e. g. , in termittent stick/slip), thermo-mechanical coupling, interaction with an in tervening lubricant and/or fluid layer, and damage of the interface (i. e. , wear) may also be featured. When taken together (or even separately!), these features have the effect of making the equations of mechanical evolu tion not only highly nonlinear, but highly nonsmooth as well. While many modern engineering simulation packages possess impressive capabilities in the general area of nonlinear mechanics, it can be contended that methodologies typically utilized for contact interactions are relatively immature in comparison to other components of a nonlinear finite element package, such as large deformation kinematics, inelastic material modeling, nonlinear equation solving, or linear solver technology.
Thank you for opening the second edition of this monograph, which is devoted to the study of a class of nonsmooth dynamical systems of the general form: ::i; = g(x,u) (0. 1) f(x, t) 2: 0 where x E JRn is the system's state vector, u E JRm is the vector of inputs, and the function f (-, . ) represents a unilateral constraint that is imposed on the state. More precisely, we shall restrict ourselves to a subclass of such systems, namely mechanical systems subject to unilateral constraints on the position, whose dynamical equations may be in a first instance written as: ii= g(q,q,u) (0. 2) f(q, t) 2: 0 where q E JRn is the vector of generalized coordinates of the system and u is an in put (or controller) that generally involves a state feedback loop, i. e. u= u(q, q, t, z), with z= Z(z, q, q, t) when the controller is a dynamic state feedback. Mechanical systems composed of rigid bodies interacting fall into this subclass. A general prop erty of systems as in (0. 1) and (0. 2) is that their solutions are nonsmooth (with respect to time): Nonsmoothness arises primarily from the occurence of impacts (or collisions, or percussions) in the dynamical behaviour, when the trajectories attain the surface f(x, t) = O. They are necessary to keep the trajectories within the subspace = {x : f(x, t) 2: O} of the system's state space.
Dynamics of Materials: Experiments, Models and Applications addresses the basic laws of high velocity flow/deformation and dynamic failure of materials under dynamic loading. The book comprehensively covers different perspectives on volumetric law, including its macro-thermodynamic basis, solid physics basis, related dynamic experimental study, distortional law, including the rate-dependent macro-distortional law reflecting strain-rate effect, its micro-mechanism based on dislocation dynamics, and dynamic experimental research based on the stress wave theory. The final section covers dynamic failure in relation to dynamic damage evolution, including the unloading failure of a crack-free body, dynamics of cracks under high strain-rate, and more. - Covers models for applications, along with the fundamentals of the mechanisms behind the models - Tackles the difficult interdisciplinary nature of the subject, combining macroscopic continuum mechanics with thermodynamics and macro-mechanics expression with micro-physical mechanisms - Provides a review of the latest experimental methods for the equation of state for solids under high pressure and the distortional law under high strain-rates of materials