Experimental and numerical investigation of AS4/8552 interlaminar shear strength under impact loading conditions

The interlaminar shear behavior of AS4/8552 laminated short beam shear (SBS) coupons were experimentally and numerically investigated under static and impact loading conditions. Experiments were conducted in a range from quasi-static (1.7x10(-5) m/s) to 3.9m/s impact velocity using a testing device (ILSS device) that has been developed and adapted in a universal testing machine and a drop tower apparatus. Regarding the interlaminar shear strength (ILSS) values, the experimental investigation showed a low to medium strain rate sensitivity with a 23% maximum ILSS decrease observed at the samples which were tested with the maximum impact speed. In the finite element framework, the novel stacked shell or 2.5D approach is investigated in the simulation of the SBS impact tests; models comprising four stacked sublaminate arrangements were capable of predicting the respective experimental results, with the maximum deviations from the respective experimental data to appear in the cases of high impact velocity.