Multiple scattering phenomena are of enormous interest in many disciplines, especially nondestructive evaluation of materials. Starting from a single fiber scattering model, a computational system is built for conducting full-scale deterministic simulations of multiple scattering of elastic waves in fiber reinforced composites.

The computational system is based on two theoretical developments. The first is the formulation of two-dimensional multiple scattering problems involving arbitrary numbers of scatterers. The resulting solutions are analytically exact, for scatterers that may be similar or dissimilar. The second theoretical development, which we name scatterer polymerization, enables assemblages of arbitrary numbers of scatterers to be modeled as a single scatterer in sequential analyses, while maintaining analytically exact solutions.

Both the multiple scattering solutions and the scatterer polymerization methodology can be used as independent tools to analyze multiple scattering problems. Each has been implemented and verified. By combining these tools, analytically exact solutions have been obtained for multiple scattering phenomena in models of composites containing thousands of fibers. The feasibility and the procedures for such full-scale simulations are demonstrated.

Finally, as a comprehensive example, a ceramic-fiber reinforced metal-matrix composite plate is modeled, and the effects on the scattered waves due to changing microstructural parameters of the composite are examined.

Thesis Committee: Professor Triantaphyllos R. Akylas     (Mechanical Engineering) Professor Henrik Schmidt     (Ocean Engineering) Professor James H. Williams, Jr.     (Committee Chairman,     Mechanical Engineering)

Displacement amplitude distribution in vicinity of fiber composite model subjected to planar incident wave. (Incident wave propagates from left and through heterogeneous composite.)