Computer simulation results for the two-point probability function of composite media

Computer simulation results are reported for the two-point matrix probability function S/sub 2/ of two-phase random media composed of disks distributed with an arbitrary degree of impenetrability lambda. The novel technique employed to sample S/sub 2/(r) (which gives the probability of finding the endpoints of a line segment of length r in the matrix) is very accurate and has a fast execution time. Results for the limiting cases lambda = 0 (fully penetrable disks) and lambda = 1 (hard disks), respectively, compare very favorably with theoretical predictions made by Torquato and Beasley and by Torquato and Lado. Results are also reported for several values of lambda that lie between these two extremes; cases which heretofore have not been examined. copyright 1988 Academic Press, Inc.