Analysis of low-velocity impact response and damage characteristics of composite laminates with rigid/soft blunt objects

Composites, known for their high specific strength, stiffness, and resistance to fatigue and corrosion, are widely used in aerospace applications. However, during service, they often undergo low-velocity blunt object impacts, which can cause hidden internal damage such as delamination, matrix cracking, and fiber debonding, leading to a reduction in compressive strength and stability. This study focuses on the AC531/CCF800H carbon fiber epoxy composite laminate, investigating both dynamic simulations and experimental validation of soft and rigid blunt object impacts. A constitutive model that incorporates strain rate effects was developed, and simulations were conducted to assess the impact responses. The errors in both the experiments and simulations are within 5%. Additionally, the study examines the effects of factors such as impact mass, energy, angle, indenter characteristics, and ply stacking sequence on damage evolution. The main conclusions are as follows: The type of punch significantly affects the impact response of a rigid punch, while the impact response of a soft punch is more greatly influenced by the size of the punch. Sudden changes in fiber direction within the laminate should be avoided to reduce the risk of failure. Highlights: Performed rigid and soft low-velocity blunt object impact tests on composite laminates. Achieved strong alignment between experimental results and simulations. Investigated delamination damage in composite laminates under low-velocity impacts. Conducted influence analysis using experimentally calibrated models.