Inter-fibre contacts in random fibrous materials: Experimental verification of theoretical dependence on porosity and fibre width

The extent of contacts between fibres in random fibrous materials was investigated and experimental verification of theoretical dependence on porosity and fibre width was done. The expressions for the expected number of contacts per fibre by considering the superposition of several two-dimensional networks and including fibre flexibility as a variable to weight the probability of contact between fibres in nearby layers, derived was difficult to verify as the number of layers was not well-defined and meaningful measures of fibre flexibility were experimentally difficult. It was noted that for modeling purposes the mean coverage of a layer could be defined by the porosity of the network, such that the number of layers in a network of a given mean coverage was well defined and the influence of fibre flexibility was accounted for. The theory, derived for general classes of stochastic fibrous materials, were applicable to networks formed from fibres with assumed dimensions.