The elastic-deformation behavior of unidirectional carbon-fiber-reinforced epoxy laminates is investigated. The effect of operating temperature decrease to 77 K on their deformation and strength is studied. The effectiveness of prediction of stiffness and compliance parameters and load-carrying ability of laminated carbon-fiber-reinforced composites has been analyzed on the basis of mechanical characteristics of the fiber and matrix.Introduction. The demand for higher load-carrying ability of constructions, their higher reliability and longer service life, as well as for smaller weight and material consumption for equipment necessitates the development of new composite materials and a wider use of the existing ones. Remarkable among composite materials are carbon-fiber-reinforced composites. The reasons limiting their use in the engineering practice are the lack of reliable experimental procedures for the determination of mechanical characteristics of reinforced composites, difficulties in the mathematical modeling of deformation processes and evaluation of the load-carrying ability of reinforced structures, and the need for new, more economical manufacturing techniques.The mechanical properties of composite materials are determined by the properties of the constituents, the structure of composites, mode of interaction at matrix-fiber interfaces, and manufacturing technique. Many mechanical parameters of composites can be calculated from known properties of constituents. However, because of the high sensitivity of some parameters (e.g., strength) to the action of many factors, which cannot be fully allowed for, the application of rigorous mathematical solutions is not always possible.The deformation and fracturing behavior of laminated fiber composites is described in numerous papers [1][2][3][4][5][6][7][8]. The most developed branch of the mechanics of heterogeneous media is apparently the branch dealing with the determination of the effective characteristics of composite materials. Expressing mechanical parameters of a composite in terms of characteristics of individual constituents gives ample scope for the design of materials with tailor-made properties. The main advantage of laminated fiber composites is the possibility to give material the anisotropy that is optimal for each particular case of its application.Deformation processes in heterogeneous media were investigated in most cases at room temperature and elevated temperatures. The use of such materials at low or cryogenic temperatures, e.g., in cryogenics or space technology, requires more detailed study of deformation and fracture processes under deep freezing conditions. The aim of the present work was to study the load-carrying ability of unidirectional carbon-fiber-reinforced epoxy laminates under static loading at room temperature and cryogenic temperatures (down to 77 K) and to examine the possibilities of predicting their strength from the structure, volume fraction and mechanical properties of the fibers and matrix.