The variation in low speed impact strength on glass fiber/Kevlar composite hybrids:

The aim of this study was to analyze the effect of hybridization on impact and residual strength in composites as well as the types of damage caused by the impacts, quantifying the delaminated area of the test specimens. Two 11-layer composite laminates were developed, one with bidirectional glass fiber woven and the other a hybrid with three layers of bidirectional aramid fiber substituting the outer layers and the middle layer of the glass fiber. The materials revealed that the hybrid laminate obtained greater impact strength withstanding one impact of 76 J, albeit with an increase in the damaged area of between 64 and 85 cm(2), resulting in a decline in mechanical properties along nearly the entire test specimen. This contrasts with what occurred in the glass fiber laminates, which recovered over 80% of their mechanical properties for a distance of 35 mm from the edge of the impactor. Moreover, it demonstrated that the variation in residual strength can be represented by an equation and that there is a relation between the damage area and the residual properties of the glass fiber material.