“…In biology and in nature, most soft connective tissues in human and animal bodies (e.g., tendons and ligaments, but also cartilage) are built from a collagen fiber network performing structural functions. In biological tissues, the extracellular matrix consists essentially of collagen fibers, and provides structural support for cells [1]; at the lower cell level, the cytoskeleton, which provides the structural resistance of the cell, is a network of F-actin filaments, playing, furthermore, an essential role in the adjustment of the biochemical activity of the cell [2]. Both the practical importance of random fiber networks and their complexity in terms of fibrous organization motivates the need to develop a quantitative understanding of the relationship between the microstructure of random fiber networks and the mechanical behavior of the respective material or system including this random fibrous microstructure at the macroscopic scale.…”