The effects of Hybridization on the mechanical performance of aramid/polyethylene intraply fabric composites

Abstract

Intraply hybrid composites have been fabricated by the open leaky-mold method in order to examine the e ects of hybridization on the mechanical performance of aramid/ polyethylene hybrid composite. The ¯exural properties, interlaminar shear strength (ILSS), and impact properties of these composites have been studied as a function of aramid ®bre content and loading direction. Two di erent stacking sequences ([0/0]4 and [0/90]4) were selected for this study, and composites of four di erent aramid ®bre contents (100, 75, 50, and 0% by volume) have been studied. In addition, scanning electron microscopy (SEM) was used to examine the fracture surfaces of the intraply hybrid composites. The ¯exural strength and modulus increased with the volume fraction of aramid ®bre, and negative deviations from the rule of mixture were observed in all intraply laminates.When the load was applied in the aramid direction, the highest ¯exural strength was obtained. This is attributed to the fact that the ¯exural strength mainly depends on whichever ®bre is present in the longitudinal direction of the specimen. In contrast with the ¯exural property results, intraply hybrid compo- sites exhibited lower ILSS values than polyethylene-®bre composites because of the di erence in the failure modes in the ¯exural and ILSS tests. In addition, intraply hybrid composites exhibited lower impact resistance than aramid ®bre composites because the level of maximum load had a major e ect on the impact absorption energy. # 1998 Elsevier Science Ltd. All rights reserved