Dynamic compressive behavior of unidirectional E-glass/vinylester composites

Results from an experimental investigation on the mechanical behavior of un idirectional fiber reinforced polymer composites (E-glass/vinylester) with 30%, 50% fiber volume fraction under dynamic uniaxial compression are prese nted. Specimens are loaded in the fiber direction using a servo-hydraulic m aterial testing system for low strain rates and a Kolsky (split Hopkinson) pressure bar for high strain rates, up to 3000/s. The results indicate that the compressive strength of the composite increases with increasing strain rate. Post-test scanning electron microscopy is used to identify the failu re modes. In uniaxial compression the specimens are split axially (followed by fiber kink band formation). Based on the experimental results and obser vations, an energy-based analytic model for studying axial splitting phenom enon in unidirectional fiber reinforced composites is extended to predict t he compressive strength of these composites under dynamic uniaxial loading condition. (C) 2001 Kluwer Academic Publishers.