Nanomechanics of hierarchical biomaterials

In this Chapter two mathematical models, forceor energy-based, are proposed to design nano-bioinspired hierarchical materials, considering strong or weak interfaces respectively. Simple formulas describing the dependence of strength, toughness and stiffness on the considered size-scale are derived, taking into account the toughening biomechanisms. A simple experimental comparison on a new two-level hierarchical grained material is also discussed. Correspondence/Reprint request: Dr. Nicola M. Pugno, Department of Structural Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy. E-mail: nicola.pugno@polito.it Nicola M. Pugno & Alberto Carpinteri 12