Abstract：In this paper, the mechanical properties of mid-temperature cured high toughness epoxy resin hybrid composites were investigated. Firstly, carbon fiber unidirectional prepreg, high-strength glass fiber unidirectional prepreg, and aramid fiber unidirectional prepreg were prepared by the hot-melt method, and a single prepreg layer and hybrid composites with different fibers were prepared by the autoclave method. Secondly, the tensile and compressive mechanical properties are tested and key performances such as stress-strain curve, strength, and stiffness were obtained. Finally, a theoretical model of equivalent tensile stiffness of hybrid fiber laminate composites was established and the Hashin strength criterion was introduced to evaluate the strength of the composites, the accuracy of which was verified by comparison with the measured values. The results showed that the interlayer mixing of different fiber prepregs allowed the hybrid composite to exert synergistic effects, optimize performance. The data obtained from the theoretical calculation model of the hybrid composite was close to the measured values, providing a theoretical basis for the strength design of the hybrid fiber.
2020, 
