Random fiber networks are present in many biological and man-made materials. Examples from the living world include the cellular cytoskeleton and various types of connective tissue. Examples from the non-living world include paper, rubber, gels, insulation and consumer products. In all these applications mechanics is important since the network performs the structural function. In this work we study the relationship between the microstructure and the mechanical properties of the network, with emphasis on identifying regimes in which large changes of the system scale behavior are triggered by small changes in system parameters. Results pertaining to multiple types of networks will be presented and contrasted, including networks made from a single type of fiber and composite networks made from fibers of multiple types, densely cross-linked, sparsely cross-linked and non-cross-linked networks. Networks of non-cross-linked nanofibers interacting by adhesion form a separate class of such systems which will receive special attention. The discussion will underline differences between the behavior of fiber networks and that of continuum bodies, which demonstrate the special position of these systems in the ranks of engineering material systems.
Prof. Picu received his PhD degree from Dartmouth College and spent two years as Research Associate at Brown University. He joined the Department of Mechanical, Aerospace and Nuclear Engineering at Rensselaer Polytechnic Institute in 1998, where he is now Professor and Associate Head. He is the author or co-author of two books, multiple book chapters and over 150 journal articles. His research focuses on mechanics of materials, and in particular, on understanding the macroscopic material behavior based on physics taking place on multiple scales. He is a fellow of ASME.