Parameter Identification of Materials and Structures


Book Description

The nature and the human creations are full of complex phenomena, which sometimes can be observed but rarely follow our hypotheses. The best we can do is to build a parametric model and then try to adjust the unknown parameters based on the available observations. This topic, called parameter identification, is discussed in this book for materials and structures. The present volume of lecture notes follows a very successful advanced school, which we had the honor to coordinate in Udine, October 6-10, 2003. The authors of this volume present a wide spectrum of theories, methods and applications related to inverse and parameter identification problems. We thank the invited lecturers and the authors of this book for their contributions, the participants of the course for their active participation and the interesting discussions as well as the people of CISMfor their hospitality and their well-known professional help. Zenon Mroz Georgios E. Stavroulakis CONTENTS Preface An overview of enhanced modal identification by L. Bolognini 1 The reciprocity gap functional for identifying defects and cracks by H. D. Bui, A. Constantinescu and H. Maigre 17 Some innovative industrial prospects centered on inverse analyses by G. Maier, M. Bocciarelli andR. Fedele 55 Identification of damage in beam and plate structures using parameter dependent modal changes and thermographic methods by Z. Mroz andK. Dems 95 Crack and flaw identification in statics and dynamics, using filter algorithms and soft computing by G. E, Stavroulakis, M. Engelhardt andH.




Terahertz Frequency Detection and Identification of Materials and Objects


Book Description

Want an overview of where the technology of terahertz detection has been going? Here it is. The technology has largely been developed around expensive and bulky femtosecond laser systems but, as described in this book, advances in semiconductor superlattice technology are leading to compact "electronic" sources such as the quantum cascade laser, two-terminal "Gunn" type oscillators and even a THz frequency amplifier. These advances towards electronic (as opposed to optical) THz systems mean that the technology will become portable and much less costly.




Identification of Materials


Book Description

This book has been written for the practicing chemist whose occasional task may be qualitative analysis. It deals with the investigation of things as they are without any limitations to the scope. It emphasizes the identification of materials - inorganic, organic, organized (biological), common, rare, described or not described in the accessible literatur- as they actually occur in nature and industry, or are met in the investigation of mishaps and crime. The description of techniques - macro to submicro - and the practice exercises have been included since the teaching of these arts is rarely a part of academic curricula and it happens with increasing frequency that chemists have to acquire them "on the job". In the systematic procedure given, emphasis is placed upon the investiga tion of minute specimens and upon acute reasoning that continuously weighs all accumulating evi9.ence. The work begins with the consideration of the history of the material under investigation. Especially when specks of all organic substance shall be identified, it should be realized that the discovery of the source - and consequently of the possibilities involve- may be the most valuable clue to an efficient solution of the problem.




Constitutive Modeling of Engineering Materials


Book Description

Constitutive Modeling of Engineering Materials provides an extensive theoretical overview of elastic, plastic, damage, and fracture models, giving readers the foundational knowledge needed to successfully apply them to and solve common engineering material problems. Particular attention is given to inverse analysis, parameter identification, and the numerical implementation of models with the finite element method. Application in practice is discussed in detail, showing examples of working computer programs for simple constitutive behaviors. Examples explore the important components of material modeling which form the building blocks of any complex constitutive behavior. - Addresses complex behaviors in a wide range of materials, from polymers, to metals and shape memory alloys - Covers constitutive models with both small and large deformations - Provides detailed examples of computer implementations for material models










Material Identification Using Mixed Numerical Experimental Methods


Book Description

Euromech 357 took place in the nice authentic monastery 'Rolduc' in Kerkrade, Holland. The objective was to bring together researchers to present their latest advancements in the relatively new domain of Material properties identification by Mixed Numerical Experimental Methods (MMM). MMM are a modem and increasingly powerful way to determine the values of unknown parameters in a numerical model by observations made on real physical test structures. Starting from the measurement of output values (like displacements, stresses, velocities, vibrations, .. ) of the real physical test structure, MMM try to update parameters in the numerical model in such a way that the computed observations match the experimental observations. It was shown clearly at the colloquium that the combined use of numerical analysing tools and sophisticated measurement techniques has created an extra degree of freedom for the design of experiments and has led to new approaches for material characterisation. The colloquium was attended by 39 participants coming from 12 different European countries. We had 23 oral presentations on the different topics of the above mentioned sessions. Each presentation was followed by an intensive discussion. Du~ to the informal atmosphere and the limited number of participants, the discussions were very lively and fruitful. The opportunity to continue to discuss common problems after dinner in a reserved place was also offered to the Euromech participants. This opportunity and the fact that the monastery was isolated (nobody could escape!) created an excellent platform for discussions and personal contacts.




Easy Identification of Plastics and Rubbers


Book Description

Polymers are found in every aspect of daily life. Materials must be carefully selected to ensure that properties match performance requirements, and this resource explains how to pick the appropriate materials.




Material Parameter Identification and Inverse Problems in Soft Tissue Biomechanics


Book Description

The articles in this book review hybrid experimental-computational methods applied to soft tissues which have been developed by worldwide specialists in the field. People developing computational models of soft tissues and organs will find solutions for calibrating the material parameters of their models; people performing tests on soft tissues will learn what to extract from the data and how to use these data for their models and people worried about the complexity of the biomechanical behavior of soft tissues will find relevant approaches to address this complexity.




Thz Identification For Defense And Security Purposes: Identifying Materials, Substances, And Items


Book Description

The principal aim of this book is to provide the reader with the understanding of the possibilities and features of THz identification as opposed to more traditional techniques such as X-rays, microwaves, etc. by elucidating and illustrating the principles of THz identification and its applications in a systematical way. Its scope includes a description of the physical principles of THz generation, transmission and detection, as well as of the applications of THz identification.The inherent advantages and potential benefits of the terahertz (THz) phenomenon, potential that encompasses various aspects such as THz sensing, imaging and material properties investigation with THz radiation for Defense (military) and security applications serve as an important stimulus for the interest in emerging THz science and technology, in particular, the very rapid growth of this new field.This text presents some of the leading fundamental research efforts towards the realization of practical THz devices applications for military and security applications. Relevant chapters contain fundamentals and/or measurements of THz radiation in solid-state materials such as high explosives (e.g. HMX, PETN, RDX, etc.), biological tissues and organic-semiconductor nanostructures. Individual chapters also address the present capabilities of THz equipment for the effective utilization of screening packages and personnel. This book contains descriptions and analyses of the most innovative research in the field; the presented material introduces novel devices and/or concepts that enhance THz source and detector performance — enabling completely new types of sensor performance at THz frequency (e.g. detection at molecular and nanoscale levels), and defining innovative sensing modalities (e.g. remote object and personnel identification) for defense and security.