The request to organize under its patronage at Poitiers in 1998 a Symposium entitled “Advanced Optical Methods and Applications in Solid Mechanics” by the International Union of Theoretical and Applied Mechanics (I.U.T.A.M.) was well received for the following two reasons. First, for nearly 20 years no Symposium devoted to optical methods in solids had been organized. Second, recent advances in digital image processing provided many new applications which are described in the following. We have the honour to present here the proceedings of this Symposium. st th The Symposium took place from august 31 to September 4 at the Institut International de la Prospective in Futuroscope near Poitiers. A significant number of internationally renowned specialists had expressed their wish to participate in this meeting. The Scientific Committee proposed 16 general conferences and selected 33 regular lectures and 17 poster presentations. Papers corresponding to posters are not differentiated in the proceedings from those that were presented orally. It is worth noting that a total of 80 participants, representing 16 countries, registered for this symposium.. The Scientific Committee deserves praise for attracting a significant number of young scientists, both as authors and as participants. Let us add our warm acknowledgements to Professor J.W. Dally and to Professor A.S. Kobayashi who, throughout the symposium preparation time, brought us valuable help.

It is true that "Nothing is more practical than theory" as Boltzmann said. Provided - however - that the assumptions on which The theory is founded are well understood. But. indeed. engineering costly experience shows that "Nothing can be more disastrous than a theory" when applied To a real task outside of practical limits of the assumptions made. Because of an homonymous identity with the considered problem. J.T.P The growing interest in Isodyne Stress Analysis and the related experience of the author show that the major monograph and reference book on the subject, Isodyne Stress Analysis by Jerzy T. Pindera and Marek-Jerzy Pindera, [27], does not of contain sufficiently detailed data on the theories and techniques experimentation. The purpose of this work is to close this gap. Thus, this work is an extension of Isodyne Stress Analysis and complementary to it. Consequently, only a short outline of the theory ofisodynes is given in Chapter 2. Only the basic concepts and relations are presented to provide the link between the underlying analytical and optical theories and the experimental techniques. One of the major purposes of a preface is to formulate and explain the chosen frame of reference in a condensed form, even when some components of it are discussed in the text. A main issue of the underlying frame of reference pertains to the roles of the abstract thinking and of the observation in cognition of reality.

A description of both the theory and practice of physical measurements that use high-sensitivity moiré - principally moiré interferometry. The focus here is on the mechanics and micromechanics of materials and structural elements and the book includes new studies published for the first time. Diverse fields are addressed: advanced composite materials, thermal stresses, electronic packaging, fracture, metallurgy, time-dependence, strain gage calibration. All the methods can be applied for whole-field measurements on nearly and solid bodies. This reader-friendly book will serve engineers and scientists who are concerned with measurements of real phenomena, while also stimulating students to pursue the treasures of experimental analysis.