Probabilistic modeling and simulation of wave speeds in random composites

Investigations of wave propagation in composite materials have been used both to experimentally measure material properties and to validate material property model characterizations. For continuous fiber reinforced composites, these characterizations often have relied on a bulk description of the effective behavior of a Representative Volume Element (RVE) and assumed ideal conditions of transverse isotropy and a well defined direction of the fibers. Analytic models, based on these composite properties and fiber directions, can then be used to predict the speeds of waves propagating through the material. The goal of this work is to develop a probabilistic simulation to examine how variations in the composite properties and small angles of mis-alignment of the fibers affect wave speed. To achieve this, a joint probability function is constructed where a dominant material property and the angle of fiber orientation are considered independent random variables. Sampling from this joint distribution produces pairs of parameters that can be input into wave speed analysis. The resulting wave speed distributions can be used to characterize the joint effects of randomness in material property and fiber angle.