The multiscale hybridization of ceramic nanoparticles incorporated into polymer matrices reinforced with hybrid fibers offers a new opportunity to develop high-performance, multifunctional composites, especially for applications in aeronautical structures. In this study, two different kinds of hybrid fibers were selected, woven carbon and glass fiber, while two different ceramic nanoparticles, alumina (Al2O3) and graphene nanoplatelets (GNPs), were chosen to incorporate into a polymer matrix (epoxy resin). To obtain good dispersion of additive nanoparticles within the resin matrix, the ultrasonication technique was implemented. The microstructure, XRD patterns, hardness, and tensile properties of the fabricated composites were investigated here. Microstructural characterization demonstrated a good dispersion of ceramic nanoparticles of Al2O3 and GNPs in the fabricated composites. The addition of GNPs/Al2O3 nanoparticles as additive reinforcements to the fiber-reinforced polymers (FRPs) induced a significant increase in the hardness and tensile strength. Generally, the FRPs with 3 wt.% nano-Al2O3 enhanced composites exhibit higher tensile strength as compared with all other sets of composites. Particularly, the tensile strength was improved from 133 MPa in the unreinforced specimen to 230 MPa in the reinforced specimen with 3 wt.% Al2O3. This can be attributed to the better distribution of nanoparticles in the resin polymer, which, in turn, induces proper stress transfer from the matrix to the fiber phase. The hybrid mode mechanism depends on the interaction among the mechanical properties of fiber, the physical and chemical evolution of resin, the bonding properties of the fiber/resin interface, and the service environment. Therefore, the hybrid mode of woven carbon and glass fibers at a volume fraction of 64% with additive nanoparticles of GNPs/Al2O3 within the resin was appropriate to produce aeronautical structures with extraordinary properties.

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A mathematical analysis is conducted on the experimental results of a study conducted on epoxy-based glass fiber reinforced plastics (GFRP) composites. Three different types of reinforcements were used in the form of woven fibers. Fabrics made of glass fibers, carbon fibers, and (glass-carbon) hybrid fibers were used at different volume fractions. E g Longitudinal moduls of elasticity of glass fibers. E c Longitudinal moduls of elasticity of carbon fibers. V m Volume fraction of matrix. V f Volume fraction of fibers. V c Volume fraction of carbon fibers.  1 Fracture stress of composites.  f Fracture stress of fibers.  m Fracture stress of matrix.  hL Fracture stress of hybrid interply composites.  g Fracture stress of glass fibers.  c Fracture stress of carbon fibers .

The improvement in the mechanical properties of composites is always an essential requirement for technological development. In this work, hybrid aluminum matrix composites fabricated using the stir casting technique. Silicon carbide and graphite used as reinforcement to improve the mechanical properties. AMCs produced by adding various volume fraction of SiC (5%, 10% and 15%) whereas fixed volume fraction (10%) of the graphite used in composites. The fabricated AMC samples were tested to determine the tensile strength, hardness and wear rate. The wear rate was determined under the different loads (10 N, 20 N, 30 N and 40 N) and sliding velocities (0.4 m/s, 0.8 m/s, 1.2 m/s and 1.6 m/s). Mechanical properties of fabricated AMCs are evaluated and compared with Al6061 alloy. The results discovered that the tensile strength and hardness increased from 490 to 710 MPa and 65VHN to 85VHN respectively with the addition of silicon carbide and graphite particles. The wear rate also increased with the increase of applied load. However, for sliding velocity it surges till 1.2 m/s then decreased steeply.

The mechanical behavior of epoxy reinforced by three different types of woven fibers was studied under compressive and bending loads. The reinforcements used were: woven glass fibers (volume fractions: 9.2%, 18.4%, 27.6%, and 36.8%), woven carbon fibers, and woven hybrid (carbon/glass) fibers at 36.8 vol.%, each. The composites were manufactured using the hand lay-up technique. Pure (unreinforced) epoxy specimens were tested as a reference material. The fracture behavior of the investigated specimens was studied both macroscopically, and using scanning electron microscopy (SEM). It was found that under compressive loads, elastic deformation is nonlinear for pure epoxy as well as epoxy reinforced by low volume fractions of glass woven fibers. At high volume fractions of glass fibers, carbon fibers, or hybrid ones, this non linearity diminished significantly. The modulus of elasticity of epoxy-reinforced by glass fibers (GF) continued to increase as a function of fiber volume fraction. At 9.2 vol.% the modulus of elasticity showed an increase of 65% compared to pure epoxy, while at 36.8 vol.% GF the improvement reached 117%. At the same volume fraction of 36.8% hybrid, and carbon reinforcements the improvements were 160%, and 178%, respectively. Similar trend of improvements were observed for the other mechanical properties under compressive loads. Under bending loads, both the flexure modulus, and flexure strength showed significant improvement as a function of glass fiber volume fraction. At the same reinforcement volume fraction, carbon fiber composites gave the highest mechanical properties, followed by hybrid composites, while glass fiber composites showed lowest improvement (about 348% improvement in flexure strength compared to pure epoxy). Fiber pull-out and debonding are the main fracture mechanisms for glass fiber reinforced epoxy, while interlaminar shearing is the main mechanism for carbon fiber composites. Hybrid (C/G) composites showed a mixed mode mechanism. The fracture process in bending proceeded in stages from the tension side inwards towards the compression side. Each stage is associated with a load drop and audible sound waves.