The scientific foundations of experimental studies of composite materials-structures are presented. Experimental methods for determining the full set of elastic and strength constants of orthotropic composites are justified. Methods of study of creep and high-speed deformation of composites, models and criteria of destruction of anisotropic fibrous composites with polymer matrix are given. Disclosed are energy criteria for developing stratification and splitting in composites. Influence of stress concentration on strength of composite parts is considered. Original models of destruction of composites are presented, as well as design methods that differ from standard ones. For students of technical universities, as well as for graduate students, engineers, researchers dealing with the problems of using composite materials in various fields of special and civil engineering.