Powder Technology, Vol.360, 598-607, 2020
Efficient measurement of the percolation threshold for random systems of congruent overlapping ovoids
The percolation behavior of composites comprising complex-shaped particles is a recurrent problem in materials science. Previous studies focused on the symmetric particles such as spheres, ellipsoids, spherocylinders, etc. The continuum percolation of a family of single axial asymmetric ovoids with tapering parameter T and aspect-ratio c/a is studied here. The geometrical properties and numerical contact detection algorithm of these ovoids are proposed firstly. Using the Monte Carlo finite-size-scaling method, the percolation threshold phi(c) of the systems comprising congruent overlapping ovoids is further determined. For a given T, phi(c) shows an initially increasing and then decreasing trend with the increasing c/a. Moreover, the value of phi(c), at the fixed c/a decreases with the increasing [T] and this trend will be more obvious with the decreasing c/a. Finally, an analytical formula is proposed to quantify the effect of ovoid's morphology, characterized by the dimensionless excluded volume of ovoid, on the percolation thresholds. (C) 2019 Elsevier B.V. All rights reserved.
Keywords:Continuum percolation threshold;Particle asymmetry;Overlapping ovoids;Geometric properties;Contact detection algorithm