Many of the next generation, high performance metal matrix composites (MMC) and intermetallic matrix composites (IMC) are reinforced with continuous fibers1. The properties of such materials depend on the fiber distribution and porosity content, among other things. The deviation from a uniform fiber density distribution and the presence of porosity are the results of non-ideal manufacturing process. Such conditions have important effects on the stiffness, strength and failure behavior of the composites. Both the reinforcing fibers and the voids interact strongly with probing fields used for material property characterization and nondestructive evaluation, including ultrasound, eddy current and x-ray.