An experimental and numerical study on the impact response and damage of composite omega stringer

This paper studies the impact response and impact damage of Omega stringer which is widely used in composite aerospace structures. The panels were impacted at stiffener edges and two impact sites were considered. The impact responses were recorded. The characteristics of contact force and its relationship with impact energy were analyzed. It is found that the shape of contact force versus time curve changes gradually with the increase of energy level. Absorbed energy, dent depth and delamination areas were obtained, and their relationships with the impact energy were discussed. Dominated damage modes and locations were demonstrated. A finite element model capable of predicting the occurrence of impact damage was employed. The progressive damage propagation was achieved. The predicted response curves and impact damage mode coincide with the test results.