Contents



Preface

Materials in their different forms and compositions are ubiquitous in our environment. Soil and rocks are the most common natural examples, whose characterization is of prime interest in many fields (geology, the oil industry, etc.). Building materials (like concrete and road surfaces), the so-called acoustic materials (plastic foams, fibrous maerials), and many others used in transport, building, infrastructures, etc., are today used in the field of noise reduction (over the last 30 years, acoustic standards have become increasingly stringent, making the fight against noise pollution a key economic factor). The materials used in structures and microstructures are now subject to increasingly stringent non-destructive controls and the demand for increased performance of these controls remains fully on the agenda. Finally, biomaterials, living tissues, bone tissues (cancellous bone, lungs, etc.) are the subject of increasingly sophisticated analyses for the diagnosis of certain pathologies such as osteoporosis, which require precision materials. Thus, whether it concerns seismic studies, environmental acoustics, non-destructive testing, or medical diagnostics, the application of acoustic techniques applied to materials still largely opens the way to fundamental studies on their propagation in complex media, the modeling of their characteristics and defects, experimental techniques used to characterize them, and the means to provide for their transfer to applications. In a broad sense, acoustic waves are an effective means for the modeling and

Acoustic waves have the ability to probe materials during propagation. The interactions between wave and medium highlight the physical properties intrinsic to materials, thus allowing the characterization of their mechanical properties. In this book, several authors with extensive industrial and academic experience have helped to showcase the potential applications of acoustic waves on materials. Considerable progress has been made in materials acoustics. High-performance theoretical models and elaborate experimental designs have been developed with the progress of sensors, allowing for better theoretical predictions and experimental characterizations. This book is divided into three chapters covering applications ranging from sound absorption (polymeric nanofibers) to propagation in complex media (porous biological structures, acoustics for interiors) and nondestructive control (nonlinearity, crystals, leakage). The book is intended to be an ideal reference for a wide audience interested in acoustic propagation in materials

For their frankness and diligence in reviewing the proposed chapters, we would like to thank all the authors who have contributed to this book. We have incorporated many of their recommendations and the book is much improved as a consequence.

Special thanks go to Anja Filipović (Commissioning Editor), Manuela Gabrić and Dolores Kuzelj (Author Service Managers) for their dedicated support in the

characterization of materials.

with various applications.

*by José A. Ballesteros, Samuel Quintana and Marcos D. Fernandez*

Beamforming Techniques
