Colloquium 626 focuses on the role of strong inhomogeneity in composite structures, widely used in modern engineering. Advanced theoretical models, computational methodologies, as well as experimental techniques for studying static and dynamic behavior of periodic, multi-layered and multi-span elastic and viscoelastic structures with high-contrast physical and geometrical properties, are within the focus of this meeting. The colloquium is aimed at bringing together a broad multidisciplinary expertise originating from numerous technological applications, including, but not restricted to manufacturing and design of photovoltaic elements, laminated glass, lightweight vehicles, energy harvesting devices, and bio-composites.