Stiff polymers, foams, and fiber networks

We study the elasticity of fibrous materials composed of
generalized stiff polymers. It is shown that, in contrast to
cellular foamlike structures, affine strain fields are generically
unstable. Instead, a subtle interplay between the architecture of
the network and the elastic properties of its building blocks leads
to intriguing mechanical properties with intermediate asymptotic
scaling regimes. We present exhaustive numerical studies based on a
finite element method complemented by scaling arguments.