Through-Thickness High Strain Rate Compressive Response of Glass/Epoxy-Laminated Composites Embedded with Randomly Oriented Discontinuous Carbon Fibers

Abstract

AbstractIn the last few decades, fiber-reinforced polymer (FRP) composites have gained much attention because of their outstanding strength-to-weight ratio, superior corrosion resistance, and excellent thermo-mechanical properties. This study presents the high strain rate (HSR) compressive behavior of woven E-glass fiber-reinforced epoxy embedded with randomly oriented discontinuous carbon fibers (RODCF). For the compressive testing of samples at HSR along the through-thickness direction, a compressive split Hopkinson pressure bar (SHPB) setup was used. Samples of cylindrical shape were used for SHPB testing, having a length to diameter ratio (L/D) of 0.75. All the samples were tested at a constant propelling gas pressure of 30 PSI and the strain rate range of 1977–2214 s−1. The amount of RODCF dispersion in the sample tested was 0.25% and 0.5% by weight of epoxy. It was observed that the mean compressive strength of the glass/epoxy (GE) sample increases up by 7.4% and 5.8% with RODCF addition of 0.25% and 0.5% by weight of epoxy, respectively. The signals obtained from the incident bar strain gauge and the transmitter bar strain gauge were used to obtain force versus time plots. The neat GE sample showed better stress equilibrium in the elastic regime as compared to GE samples containing RODCF. Dynamic plots of compressive strain rate versus time, true stress versus true strain as well as forces versus time were obtained for each type of sample and discussed.KeywordsFiber-reinforced polymerHigh strain rateSplit Hopkinson pressure barGlass/epoxyDiscontinuous carbon fibers