The objective of this study was to develop a whole-field experimental stress analysis method for composite structures. A data-gathering system, using the optical technique of laser speckle interferometry, was used to capture deformation of bodies under load on a film record. The speckle interferograms were analyzed by a computer-aided scanning system. A mathematical and geometrical interpretation of interferometric data is presented. The interferograms were analyzed at strategic image points on the test specimens to obtain displacement data which was used to calculate strains, shearing strains, and correlated with shearing stresses. Anisotropic elastic constants such as Young's modulus, shear modulus, and Poisson's ratio were calculated. A full-field aperture analysis was used as a tool to qualitatively observe the free edge effects of shear specimens. The techniques presented in this report are significant because full-field or discrete information can be obtained from any point rather than averaging data from a small region. (Author).

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In this unique book, Shchepinov and his colleagues introduce and discuss the development and application of the increasingly important technique; holographic and speckle interferometry employed in the investigation of structure and material deformation and fracture processes. The authors consider the main physical and metrological aspects of interferometry from the deformation analysis viewpoint, emphasizing the need for (and the difficulties in obtaining) high quality and accurate fringe patterns. The advantages and outstanding features of the techniques are discussed in the second part of the book and these are compared with conventional methods of experimental mechanics. The book is illustrated with numerous unique interferograms to demonstrate the various fringe patterns which must be quantitively interpreted to obtain strain and stress values with the required accuracy. All fringe patterns presented are primary sources of the corresponding displacement and strain distributions contained in the book. The results illustrate how holographic and speckle interferometry can be used for development in various scientific and applied subjects in the fields of solid and fracture mechanics. Written specifically for researchers and engineers specializing in the strength of structures and materials, this book will also serve to introduce students to the fundamentals of holographic and speckle interferometry and the way these methods can be applied in experimental mechanics.

All structures suffer from stresses and strains caused by factors such as wind loading and vibrations. Stress analysis and measurement is an integral part of the design and management of structures, and is used in a wide range of engineering areas. There are two main types of stress analyses – the first is conceptual where the structure does not yet exist and the analyst has more freedom to define geometry, materials, loads etc – generally such analysis is undertaken using numerical methods such as the finite element method. The second is where the structure (or a prototype) exists, and so some parameters are known. Others though, such as wind loading or environmental conditions will not be completely known and yet may profoundly affect the structure. These problems are generally handled by an ad hoc combination of experimental and analytical methods. This book therefore tackles one of the most common challenges facing engineers – how to solve a stress analysis problem when all of the required information is not available. Its central concern is to establish formal methods for including measurements as part of the complete analysis of such problems by presenting a new approach to the processing of experimental data and thus to experimentation itself. In addition, engineers using finite element methods will be able to extend the range of problems they can solve (and thereby the range of applications they can address) using the methods developed here. Modern Experimental Stress Analysis: Presents a comprehensive and modern reformulation of the approach to processing experimental data Offers a large collection of problems ranging from static to dynamic, linear to non-linear Covers stress analysis with the finite element method Includes a wealth of documented experimental examples Provides new ideas for researchers in computational mechanics

The design of mechanical components for various engineering applications requires the understanding of stress distribution in the materials. The need of determining the nature of stress distribution on the components can be achieved with experimental techniques. Applications and Techniques for Experimental Stress Analysis is a timely research publication that examines how experimental stress analysis supports the development and validation of analytical and numerical models, the progress of phenomenological concepts, the measurement and control of system parameters under working conditions, and identification of sources of failure or malfunction. Highlighting a range of topics such as deformation, strain measurement, and element analysis, this book is essential for mechanical engineers, civil engineers, designers, aerospace engineers, researchers, industry professionals, academicians, and students.

A new experimental technique has been devised to measure residual stresses in ductile materials with a combination of laser speckle pattern interferometry and spot heating. The speckle pattern interferometer measures in-plane deformations while the heating provides for very localized stress relief. The residual stresses are determined by the amount of strain that is measured subsequent to the heating and cool-down of the region being interrogated. A simple lumped parameter model is presented to provide a description of the method. This description is followed by presentations of the results of finite element analyses and experimental results with uniaxial test specimens. Excellent agreement between the experiments and the computer analyses were obtained.

Fundamental measurement problems in engineering, mechanics, manufacturing, and physics are now being solved by powerful optical methods. This book presents a lucid, up-to-date discussion of these optical methods. Beginning from a firm base in modern optics, the book proceeds through relevant theory of interference and diffraction and integrates this theory with descriptions of laboratory techniques and apparatus. Among the techniques discussed are classical interferometry, photoelasticity, geometric moire, spatial filtering, moire interferometry, holography, holographic interferometry, laser speckle interferometry, and video-based speckle methods. By providing a firm base in the physical principles and at the same time allowing the reader to perform meaningful experiments related to the topic being studied, the book offers a unique user-oriented approach that will appeal to students, researchers and practising engineers.

The Springer Handbook of Experimental Solid Mechanics documents both the traditional techniques as well as the new methods for experimental studies of materials, components, and structures. The emergence of new materials and new disciplines, together with the escalating use of on- and off-line computers for rapid data processing and the combined use of experimental and numerical techniques have greatly expanded the capabilities of experimental mechanics. New exciting topics are included on biological materials, MEMS and NEMS, nanoindentation, digital photomechanics, photoacoustic characterization, and atomic force microscopy in experimental solid mechanics. Presenting complete instructions to various areas of experimental solid mechanics, guidance to detailed expositions in important references, and a description of state-of-the-art applications in important technical areas, this thoroughly revised and updated edition is an excellent reference to a widespread academic, industrial, and professional engineering audience.