High-rate in-plane shear testing of IM7/8552 using the Split Hopkinson Tension Bar

The high-rate in-plane shear properties of IM7/8552 carbon/epoxy composite material were investigated using a split Hopkinson tension bar featuring constant impedance mountings and semiconductor strain gauges in order to maximize the quality of the load signal. The in-plane shear response up to failure was evaluated using digital image correlation and correction terms for fiber rotation. The data confirmed previously determined experimental data reporting an increase of in-plane shear strength with increasing loading rate: In-plane shear strengths of 135 and 175 MPa were measured for strain rates of 320 and 2600  s−1, respectively. The results indicate that a Johnson-Cook-type semilogarithmic scaling law can be used to describe the evolution of in-plane shear strength with increasing loading rate.