Conventional carbon fiber-reinforced plastics (CFRP) have extensively been used as structural elements in a myriad of sectors due to their superior mechanical properties, low weight and ease of processing. However, the relatively weak compression and interlaminar properties of these composites limit their applications. Interest is, therefore, growing in the development of hierarchical or multiscale composites, in which, a nanoscale filler reinforcement is utilized to alleviate the existing limitations associated with the matrix-dominated properties. In this work, the fabrication and characterization of hierarchical composites are analyzed through the inclusion of graphene to conventional CFRP by vacuum-assisted resin infusion molding.

This article addresses the experimental characterization of the mechanical properties of three types of woven fabric composites taking into account the effects of hygrothermal and hygrothermomechanical aging. Characterization was carried out using the mode I, double cantilever beam (DCB) and the mode II, end notched flexural (ENF) interlaminar fracture tests in order to determine the loss in crack propagation resistance. The materials used were two types of woven (2/2 Twill, 8-Harness Satin) glass fiber, and 8-Harness Satin carbon fiber. The matrix was polyetherimide (PEI). The critical values of the energy release rate in mode I and mode II were calculated using the corrected beam theory. The material reinforced with 8-Harness Satin glass fiber presented the best behavior in mode I and mode II. The decrease in fracture strength is more important in the material reinforced with carbon fiber.