Measurement Of Residual And Applied Stress Using Neutron Diffraction

The accurate, absolute, and non-destructive measurement of residual stress fields within metallic, ceramic, and composite engineering components has been one of the major problems facing engineers for many years, and so the extension of X-ray methods to the use of neutrons represents a major advance. The technique utilizes the unique penetrating power of the neutron into most engineering materials, combined with the sensitivity of diffraction, to measure the separation of lattice planes within grains of polycrystalline engineering materials, thus providing an internal strain gauge. The strain is then converted to stress using calibrated elastic constants. It was just over ten years ago that the initial neutron diffraction measurements of residual stress were carried out, and during the ensuing decade measurements have commenced at most steady state reactors and pulsed sources around the world. So swift has been the development of the field that, in addition to fundamental scientific studies, commercial measurements have been made on industrial components for several years now. The use of neutrons is ideally suited to the determination of triaxial macrostress tensors, macrostress gradients, and microstresses in composites and multiphase alloys as well as deformed, plastically anisotropic metals and alloys. To date, it has been used to investigate welded and heat-treated industrial components, to characterize composites, to study the response of material under applied loads, to calibrate more portable methods such as ultrasonics, and to verify computer modelling calculations of residual and applied stress.

While residual stress can be a problem in many industries and lead to early failure of component, it can also be introduced deliberately to improve lifetimes. Knowledge of the residual stress state in a component can be critical for quality control of surface engineering processes or vital to performing an accurate assessment of component life unde

Over the past 25 years the field of neutron diffraction for residual stress characterization has grown tremendously, and has matured from the stage of trial demonstrations to provide a practical tool with widespread applications in materials science and engineering. While the literature on the subject has grown commensurately, it has also remained

Over the past 25 years the field of neutron diffraction for residual stress characterization has grown tremendously, and has matured from the stage of trial demonstrations to provide a practical tool with widespread applications in materials science and engineering. While the literature on the subject has grown commensurately, it has also remained

The field of stress analysis has gained its momentum from the widespread applications in industry and technology and has now become an important part of materials science. Various destructive as well as nondestructive methods have been developed for the determination of stresses. This timely book provides a comprehensive review of the nondestructive techniques for strain evaluation written by experts in their respective fields. The main part of the book deals with X-ray stress analysis (XSA), focussing on measurement and evaluation methods which can help to solve the problems of today, the numerous applications of metallic, polymeric and ceramic materials as well as of thin-film-substrate composites and of advanced microcomponents. Furthermore it contains data, results, hints and recommendations that are valuable to laboratories for the certification and accreditation of their stress analysis. Stress analysis is an active field in which many questions remain unsettled. Accordingly, unsolved problems and conflicting results are discussed as well. The assessment of the experimentally determined residual and structural stress states on the static and dynamic behavior of materials and components is handled in a separate chapter. Students and engineers of materials science and scientists working in laboratories and industries will find this book invaluable.

With contributions from 24 authorities from around the world, this handbook provides the most authoritative reference resource available on the impact of residual stresses on mechanical properties of materials and structures. You'll find detailed descriptions of a full range of measuring techniques, including hole drilling, layer removal, sectioning, X-ray diffraction, neutron diffraction, and ultrasonic methods. A variety of case studies which illustrate use of specific techniques are included to facilitate your understanding. Design and structural engineers, metallurgists, and material scientists will find a wealth of valuable information covering recent developments in residual stress measuring techniques, with guidelines provided for selecting the right measuring strategy for each specific application, and many helpful tips for improving quality control.

Stress develops during the synthesis and use of materials such as alloys and compounds. Measurement of residual stress is essential to improve the quality of synthesized materials and diagnosis of failure and/or reliability of fabricated components.

An introductory and intermediate level handbook written in pragmatic style to explain residual stresses and to provide straightforward guidance about practical measurement methods. Residual stresses play major roles in engineering structures, with highly beneficial effects when designed well, and catastrophic effects when ignored. With ever-increasing concern for product performance and reliability, there is an urgent need for a renewed assessment of traditional and modern measurement techniques. Success critically depends on being able to make the most practical and effective choice of measurement method for a given application. Practical Residual Stress Measurement Methods provides the reader with the information needed to understand key residual stress concepts and to make informed technical decisions about optimal choice of measurement technique. Each chapter, written by invited specialists, follows a focused and pragmatic format, with subsections describing the measurement principle, residual stress evaluation, practical measurement procedures, example applications, references and further reading. The chapter authors represent both international academia and industry. Each of them brings to their writing substantial hands-on experience and expertise in their chosen field. Fully illustrated throughout, the book provides a much-needed practical approach to residual stress measurements. The material presented is essential reading for industrial practitioners, academic researchers and interested students. Key features: • Presents an overview of the principal residual stress measurement methods, both destructive and non-destructive, with coverage of new techniques and modern enhancements of established techniques • Includes stand-alone chapters, each with its own figures, tables and list of references, and written by an invited team of international specialists