Research on the Low‐Velocity Impact Response of 3D Integrated Multi‐Cellular Knitted Composites: Experimental and Finite Element Modeling

ABSTRACT This study investigates the low‐velocity impact behavior of 3D integrated multi‐cellular knitted composites (3D‐IMKC) manufactured from E‐glass yarns using the vacuum‐assisted resin transfer molding (VARTM) process. Three knitted configurations with distinct connector geometries—U‐shaped, V‐shaped, and D‐shaped—were fabricated to examine the influence of internal topology on impact resistance and damage evolution under an impact energy of 25.62 J. Drop‐weight impact tests revealed that connector geometry significantly governs the force–time response, energy absorption capability, and failure morphology. The U‐shaped architecture exhibited the highest peak contact force of approximately 1380 N, whereas the V‐shaped and D‐shaped configurations demonstrated reductions in peak load capacity of approximately 12% and 50%, respectively. However, the V‐shaped structure demonstrated the highest energy absorption (~28.75 J), characterized by progressive deformation mechanisms including connector rotation and core buckling. In contrast, the D‐shaped core showed the lowest resistance to perforation, exhibiting localized punching and severe structural degradation. A multiscale finite element model, implemented via a Python‐based Abaqus plugin, successfully reproduced the experimental response, predicting peak contact forces with a deviation below 4%. The proposed framework provides an effective tool for analyzing complex knitted composite architectures and offers critical design insights for developing lightweight structures with tailored impact tolerance.