This small book intends to build a bridge between the aspects of Optics and of Mechanics that are involved in the application of holographie interferometry to deformation analysis of opaque bodies. As such, it follows in some way the footsteps ofthe late Prof. H. Favre, who already in 1927 proposed to use interferometry for deformation measurements (refer to his thesis "Sur une nouveHe methode optique de determination des tensions interieures"). Many a concept also originates from the research and lectures of Prof. W. Prager in continuum mechanies, Profs. D.C. Drucker and C. Mylonas in experimental mechanics, Prof. C.R. Steele in sheH theory and Prof. W. Lukosz in physieal optics. Further stimulation arose in dis cussions about holography with Profs. R. Dändliker, J. Der Hovanesian and H. Tiziani as weH as with Drs. B. Ineiehen and F.M. Mottier. The contribution of Drs. W. Wüthrich, P. Bohler and G. Teichmann must also be acknowledged, the latter more partieularly for rendering valuable assistance on the delieate points of tensor calculus as weH as in the drawing of the figures. FuH gratitude must also be expressed to those who made the publication of this book possible: Dr. D. MacAdam who openheartedly accepted it in his series, Dr. H. Lotsch and the collab orators of Springer-Verlag, Mr. P. Hagnauer who revised the original text and Mrs. L. Wehrli whose patience was tried in carefully typing the manuscript, whieh Mr. F. Dufour read over again

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.

In this book series on Optical Sciences, holography has been the subject of three previous volumes. In particular, Vol. 16, written by one of us (W. S. ) and Dr. M. Dubas, treated holographic interferometry of opaque bodies from the standpoint of deformation analysis. However, the fundamental principles of holography are developed there only briefly in preparation for a discussion of interference fringe modifications. This new volume in the series is intended to consider in detail many topics which were previously omitted, such as the deformation or distortion of holo graphic images, the theory of volume holograms, composite or multiplex holo graphy, holographic interferometry of transparent media, time dependent effects, holographic contouring, and applications of fringe modifications to the deformation of opaque bodies. In addition, these and other subjects will be treated with the same unifying concept developed in Vol. 16, but with an addi tional emphasis on those features that have their origins in classical optics, espe cially the small-wavelength approach, the coupled-wave theory, and the Seidel aberrations. Since the field of holography and its various applications is growing rapidly, it is impossible to be comprehensive in a single book. Every effort has beep. made to avoid unnecessary duplication of Vol. 16. For example, displace ment and fringe localization problems are only briefly discussed, while some modification techniques (e. g. , sandwich holography) are not included. When needed, however, the reader is directly referred to complementary publications.

The basic problems of quantitative determination of mechanical strain of vibrating object through holographic interferometry are discussed. Time-average holography, which is most commonly used for holographic vibration analysis, can not be combined with heterodyne evaluation, since the interference fringes are already frozen in the hologram. Synchronized double-pulse holography can be employed in the same manner as pulsed double exposure holography. Moreover, real-time holography allows to investigate the temporal behaviour of vibrations, but only at one or a few points sitaneously, depending on the number of detectors employed. Both methods were tested. The method uses essentially heterodyne holographic interferometry for the quantitative determination of the surface displacement from the fringe pattern in the image plane. Finally, a nearly fully automated camera with photothermoplastic film is presented to achieve fast and dry in-situ recording and processing of holograms with high diffraction efficiency. (Author).

The basic problems of quantitative determination of mechanical strain through holographic interferometry are discussed. A solution based on the calculation of local derivatives of the holographically recorded surface displacements is described. This method uses essentially heterodyne holographic interferometry for the quantitative determination of the surface displacement from the fringe pattern in the image plane. With this technique the interference phase can be measured with an accuracy and reproducibility of + or - 0.3 deg at any point in the fringe pattern, corresponding to an interpolation of better than .001 of one fringe. Numerical examples are given for the sensitivity and accuracy of surface strain measurements and the determination of bending and torsion. Experimental results for bending and torsion of arbitrarily curved and twisted space beams, such as turbine blades, are reported. Accuracy and agreement with theory are within a few percent. (Author).

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.

Progress in Optics