Abstract In this study, hat-stiffened composite panels, which are widely employed in the aerospace industry, were fabricated using the vacuum infusion method. To enhance the strength of the hat-stringer composites, a composite I-beam was integrated into the panel, and its impact performance under low-velocity loading was investigated. It was determined that the incorporation of the I-beam into the hat-stiffened composite panels increased the maximum impact force by up to 2.5 times. For the numerical analyses, the LS-DYNA finite element software package was utilized, and the impact test results were examined in three dimensions based on the Hashin failure criterion. Geometric variations that occurred in the hat-stringer and I-beam during the manufacturing process were incorporated into the numerical model. The correlation between the experimental data and the modified numerical results is presented in detail.
Uslu et al. (2026) studied this question.