Chapter 7: Nonlinear elasticity

patrick rasolofosaon

This book can be considered as a natural continuation of the book entitled 'Acoustics of Porous Media', co-authored by Thierry Bourbié, Olivier Coussy and Bernard Zinszner, and issued by our laboratory in 1986 for the French version, and in 1987 for the English version. However, here the clear guideline is experimentation. In contrast to previous books, all the techniques, from the most conventional (using piezoelectric transducers) to the most recent spaceage methods (as laser ultrasonics) are detailed. Furthermore the book is mainly based on experimental data allowing to select the most appropriate theories for describing elastic wave propagation in rocks. Emphasis on Nonlinear elasticity and Seismic anisotropy are also originality of the book. A part of the book also focuses on the history of the different sub-fields dealt with, having in mind that the knowledge of the history of a field contributes to understanding the field itself. For instance, in spite of the clear anteriority of their work the names of the Persian mathematician, physicist and optics engineer Ibn Sahl, and of the English astronomer and mathematician Thomas Harriot are unfairly not, or rarely, associated with the law of refraction, compared to the names of the Dutch astronomer and mathematician Willebrord Snell van Royen, known as Snellius, and of the French philosopher and writer René Descartes, as detailed in the first chapter.