Dynamic testing of composite laminates with a tensile split Hopkinson bar

A tensile version of the split Hopkinson bar, suitable for dynamic resting of laminated composite materials, is introduced. A pulse duration of 200-25 0 microseconds and peak strain rates of up to 350 s(-1) are obtained. Tests performed on a quasi-isotropic lay-up of graphite-epoxy show good repeatab ility. To determine the significance of rate-dependency, static tests were also performed using an identical specimen configuration as in the dynamic tests. Comparison of the Hopkinson bar tests to those performed at a quasi- static rate on a hydraulic test machine shows the rate-dependency of this l ay-up of graphite-epoxy. Tensile strength and fracture strain are found to be higher for dynamic testing.