Experimental and Simulation Study on Low-Velocity Impact Induced Delamination Damage in CFRP T-shaped Stringer Stiffened Panel

Abstract This study systematically investigates the low-velocity impact damage behavior of carbon fiber reinforced polymer stiffened panels through experimental and numerical simulation approaches. Within the 35 J impact energy, two material configurations - Configuration I (China Composites Corporation) and Configuration II (Toray Industries, Japan) - exhibit markedly distinct failure modes: the former demonstrates baseplate delamination with intact stiffeners, while the latter shows stiffener damage accompanied by extensive delamination. The damage progression was successfully captured through finite element analysis employing a cohesive zone model, with its accuracy validated against experimental data. Through comparative analysis of experimental and simulation data, this study reveals that delamination in CFRP stiffened panels under low-velocity impact is primarily governed by interfacial tangential strength. Enhancement of tangential strength can reduce delamination area, while variations in normal strength demonstrate negligible effects.