Research Information System
Arabian Journal for Science and Engineering, vol.47, no.12, pp.16135-16148, 2022 (SCI-Expanded)
The present study investigates tensile strength and impact resistance of alumina (Al2O3) filled carbon-S2-glass (CG) and carbon-Kevlar-49 (CK) reinforced epoxy hybrid composites, for three, five and seven layers. Nanoparticles of 40-nm size are dispersed in the epoxy matrix at a concentration of 2 wt.% of the matrix. Composites are manufactured employing the vacuum-assisted resin transfer molding method. Mechanical properties are determined by tensile and Charpy-V-notch impact tests. It is shown that number of layers affects tensile and impact characteristics. Ultimate tensile stress of CK laminates increases by approximately 35%; however, it decreases for CG laminates by 20%, per addition of a single layer of a particular fiber, whereas a similar trend in elongation at break and tensile modulus is observed for both types of composites. Stress–strain curves follow a particular pattern, characterized by unstable delamination and gradual fragmentation of a single laminae. With the addition of nanoparticles, both modulus of elasticity and ultimate tensile stress are greatly decreased by approximately one and two orders of magnitude. Values of ultimate tensile stress and strain increase with number of layers for CK laminates, while it is the other way around for CG laminates. Charpy impact tests reveal that impact energy and impact strength of the CG laminates are larger than those of the CK laminates; and impact strength increases with number of layers. Micro-scale damage analysis is conducted via scanning electron microscope (SEM) technique. Accordingly, fiber breakage, fiber pull-out and matrix cracks occur in the composites.