Experimental amelioration of flexural behavior under cryogenic conditioning through inter-ply fiber hybridization in FRP composites

Inter-ply fiber hybridization seems to be a very propitious technique to improve the mechanical properties of FRP composites. However, the mechanical response of these hybrid composites under cryogenic conditions has not yet fully explored experimentally. In this research paper, a systematic examination of the flexural behavior of hybrid samples conditioned at ambient temperature, zero, as well as cryogenic conditions has been carried out. In this study, hybrid polymer composites have been pondered by carbon and glass fiber as reinforcement. Fractography of the fractured samples was done by using scanning electron microscopy for featuring failure mechanisms and to validate most of the reasons mentioned in the literature regarding alteration in the properties at each tested condition. These composite materials performance might be governed by polymer relaxation at lower temperatures, matrix cracking, cryogenic hardening, and compressive residual stresses due to the difference in the coefficient of thermal expansion of the fibers and matrix. Fiber hybridization method significantly alleviated the limitations of carbon fiber such as low stain to failure, catastrophic failure, and its cost for the application to cryogenic fuel tanks for space vehicles, support structures of superconducting magnets, etc.