In-plane mechanical properties and energy absorption of non-uniform variable-thickness honeycomb structures
摘要
To address the high energy demands in aerospace protective systems, this study proposes a bioinspired nonuniform variable-thickness honeycomb (NVTH) structure derived from human femur morphology, aiming to enhance energy absorption beyond conventional hexagonal honeycombs. A mechanical model integrating the upper bound theorem of plastic mechanics and virtual work principle was developed to analyze NVTH’s structural behavior. Finite element simulations systematically evaluated deformation modes, stress-strain responses, load-bearing capacity, and energy absorption characteristics. Key findings reveal that NVTH achieves 26.26% greater energy absorption than standard hexagonal honeycombs and 25.04% improvement over traditional negative Poisson’s ratio (NPR) configurations. The thickness-gradient design enhances buckling resistance by 23.33% compared to uniform counterparts, while exhibiting NPR properties and multi-stage collapse mechanisms under quasi-static compression. Experimental validation confirms the structure’s synergistic performance enhancements through controlled material redistribution. The proposed methodology demonstrates extensibility to diverse metamaterial architectures, including NPR variants, offering a generalized framework for optimizing energy-absorbing structures in advanced engineering applications. This biomimetic approach bridges anatomical efficiency with engineered material systems, establishing new pathways for lightweight, high-performance protective solutions in aerospace and related fields.