This work addresses the performance of novel metallic hollow-sphere structures (MHSS) in sandwich panels. Numerical finite-element analyses and experimental tests are described.

Multifunctional Metallic Hollow Sphere Structures are an emerging new material category, belonging like metal foams to the class cellular metals. Thanks to their advantageous mechanical and sound absorbing properties, Multifunctional Metallic Hollow Sphere Structures are very promising for various applications and our technological knowledge makes them ready for industrial usage. This reference gives a complete overview on this new materials class, the fundamentals, the applications and the perspective for future use. It provides the foundations for a profound understanding (production and processing), their physical properties (surface properties and stalility) and applicaltion (in particular for sound absorption and chemical adsorption in structural parts). The book is written for material scientists, product designers and developers as well as academic researches and scientists.

Common engineering materials reach in many demanding applications such as automotive or aerospace their limits and new developments are required to ful ll increasing demands on performance and characteristics. The properties of ma- rials can be increased for example by combining different materials to achieve better properties than a single constituent or by shaping the material or c- stituents in a speci c structure. Many of these new materials reveal a much more complex behavior than traditional engineering materials due to their advanced str- ture or composition. Furthermore, the classical applications of many engineering materials are extended to new ranges of applications and to more demanding en- ronmental conditions such as elevated temperatures. All these tendencies require in addition to the synthesis of new materials, proper methods for their m- ufacturing and extensive programs for their characterization. In many elds of application, the development of new methods and processes must be acc- plished by accurate and reliable modeling and simulation techniques. Only the interaction between these new developments with regards to manufacturing, m- eling, characterization, further processing and monitoring of materials will allow to meet all demands and to introduce these developments in safety-relevant applications. The 3rd International Conference on Advanced Computational Engineering and Experimenting, ACE-X 2009, was held in Rome, Italy, from 22 to 23 June 2009 with a strong focus on the above mentioned developments.

The book focuses especially on the application of SHM technology to thin walled structural systems made from carbon fiber reinforced plastics. Here, guided elastic waves (Lamb-waves) show an excellent sensitivity to structural damages so that they are in the center of this book. It is divided into 4 sections dealing with analytical, numerical and experimental fundamentals, and subsequently with Lamb-wave propagation in fiber reinforced composites, SHM-systems and signal processing. The book is designed for engineering students as well as for researchers in the field of structural health monitoring and for users of this technology.