Elasticity of Poissonian fiber networks

An effective-medium model is introduced for the elasticity of two-dimension al random fiber networks. These networks are commonly used as basic models of heterogeneous fibrous structures such as paper. Using the exact Poissoni an statistics to describe the microscopic geometry of the network, the tens ile modulus can be expressed by a single-parameter function. This parameter depends on the network density and fiber dimensions, which relate the macr oscopic modulus to the relative importance of axial and bending deformation s of the fibers. The model agrees well with simulation results and experime ntal findings. We also discuss the possible generalizations of the model.