Effect of Support Boundaries on Impact Response and Residual Properties of Thick‐Ply and Hybrid Laminates

Boundary conditions are receiving increasing attention in the overall design of composite structures. This study explores the influence of two typical bottom support boundaries on the impact response and residual properties of thick‐ply and ply‐level hybrid laminates. Low‐velocity impact (LVI) tests were conducted to compare the structural response of laminates under two different bottom support conditions. Finite element (FE) models using the LaRC05 failure criterion were developed to further investigate the influence mechanism of boundary constraints. Compression after impact (CAI) tests were also performed to evaluate the effect of support boundaries on the residual properties. Results reveal that, the bottom support boundary significantly influences the impact response of laminated composites. Although the small open‐window support boundary limits out‐of‐plane deflection, it increases local relative deformation and amplifies impact damage, thereby leading to reduced residual stiffness and strength in laminated composites. Furthermore, hybrid laminates demonstrate superior impact damage resistance and CAI strength compared to thick‐ply laminates under both support conditions. These findings suggest that compliant support boundaries offer an effective means of enhancing impact resistance in laminated composites.