Review of barely visible impact damage and residual strength in carbon/glass fiber hybrid ship hull structures

Carbon/glass fiber hybrid composites offer high specific strength and modulus, excellent toughness, and cost-effectiveness, making them promising materials for lightweight ship structures. During manufacturing, assembly, and service, ship structures are frequently subjected to low-velocity impacts caused by dropped tools, floating debris, berthing, and grounding. These impacts can cause barely visible impact damage (BVID), which is characterized by minimal visible surface damage despite potentially extensive internal damage. Such damage often involves matrix cracking, fiber fracture, and delamination, which can substantially reduce the residual strength of the structure. This paper focuses on carbon/glass fiber hybrid stiffened panels for ship structures and systematically reviews recent advances in the understanding of hybrid effects, BVID evolution mechanisms, and residual strength assessment of damaged structures. The effects of hybrid configurations on impact performance, the initiation and propagation of BVID, and the mechanisms underlying residual strength degradation are comprehensively analyzed. Key advances and limitations in understanding hybrid effects, characterizing BVID across multiple scales, and predicting residual strength are highlighted. Future research directions are also discussed, with particular emphasis on the interaction of complex loading conditions, marine environmental effects, damage-tolerant design, and standardization. The findings of this review are intended to inform impact-resistant design, structural condition assessment, and maintenance decision-making for composite ship structures.