The current situation with regard to the use of high-performance composites is one of seeking a reliable means of characterizing the fundamental properties and/or behavior of composite materials. The employment of such materials in vi tal structural applications require criteria as part of the materials selection and design procedures. However, the principal limitation of the many currently available procedures, most of which were borrowed from the metal i"ndustry, is its intrinsic restriction to single phase materials. They cannot adequately ac count for the variations in the constituents or...