A Reduced Computational Model for Prediction of Electrical Resistance in Fibrous Composites

The effective conductivity of a fibrous composite is investigated using the Monte Carlo simulation scheme and the finite-element method. The conductive fibers are modeled as randomly distributed resistors in a nonconductive matrix. The gap elements are constructed between neighboring fibers to model the interfiber contact. The resistance of a gap element is defined as a function of the gap distance and the contact area. The quantitative analysis is performed on the basis of an equivalent resistor network, and the relationships between the overall conductivity and various geometric parameters such as the volume fraction, the fiber aspect ratio, the fiber orientation angle, the tunneling effect, and the fiber length distribution, have been studied. The key results such as the percolation thresholds have been validated by the data reported in the literature. Compared to the full three-dimensional simulations, the reduced model presented in this work is computationally more efficient and can be used in other applications as well.