Compression failure analysis of composite grid-stiffened structures: Effects of skin layup schemes and grid layout configurations

Advanced grid-stiffened (AGS) composite structures are widely used in aerospace engineering due to their excellent specific strength and high damage tolerance. Previous studies have predominantly focused on the optimization of grid stiffener configurations, while the effects of skin layup schemes on structural performance have received comparatively little attention. This study systematically investigates the influence of skin layup strategies, namely the novel Double-Double (DD) and conventional Legacy Quad Laminate (LQL) methods, on the buckling and failure behaviors of three representative AGS structures. Both experimental tests and numerical simulations are conducted to investigate the buckling and post-buckling failure behaviors of AGS structures. The results indicate that DD layup offers significant advantages in improving axial stiffness, while the grid layout has more effects on the failure strength of the structures. These findings show that skin layup schemes and grid layout configurations jointly affect the mechanical performance of AGS structures and should be considered together in their optimal design.