Zheng Junyuan, Tian Guangdong
School of Mechanical-Electronic and Vehicle Engineering, Beijing University of Civil Engineering and Architecture, Beijing 100044, China.
Polymers (Basel). 2025 Jun 19;17(12):1717. doi: 10.3390/polym17121717.
Honeycomb structures are widely constructed as cores in sandwich panels with lightweight characteristics and excellent out-of-plane properties. However, their in-plane performances are significantly inferior. This research proposed a novel isotropy-enhanced honeycomb (IEH) with interleaved layers, which is constructed by offsetting the initial seed distributions across layers and then generating hexagonal cells via Voronoi tessellation. Numerical models with three layer-to-layer interval gradients were developed for simulations, and corresponding samples were additively manufactured for experimental validations. The in-plane and out-of-plane performances of IEH and the regular hexagonal honeycombs (RHHs) were comprehensively compared and investigated from quasi-static compression, energy absorption, mechanical properties, and dynamic loading. The results demonstrated that the IEH extremely enhances the in-plane properties by around 500% compared to the RHH, including stiffness, strength, plateau stress, and specific energy absorption (SEA). Although the improvements come at the expense of a partial reduction in out-of-plane stiffness, strength, and SEA, the in-plane performances of IEH reach approximately 70% of their out-of-plane performances, greatly improving the structural isotropy. Introducing layer-to-layer interval gradient leads to a slight reduction in out-of-plane mechanical properties while improving the early-stage deceleration under impact. These findings promote the considerable potential of sandwich panels utilizing IEH cores for applications requiring enhanced resistance to multi-directional impacts.
蜂窝结构作为夹芯板的芯材被广泛构建，具有轻质特性和优异的面外性能。然而，它们的面内性能明显较差。本研究提出了一种具有交错层的新型各向同性增强蜂窝（IEH），它是通过在各层之间偏移初始种子分布，然后通过Voronoi镶嵌生成六边形单元而构建的。开发了具有三种层间间隔梯度的数值模型进行模拟，并通过增材制造相应的样品进行实验验证。从准静态压缩、能量吸收、力学性能和动态加载等方面，对IEH和正六边形蜂窝（RHH）的面内和面外性能进行了全面比较和研究。结果表明，与RHH相比，IEH的面内性能极大地提高了约500%，包括刚度、强度、平台应力和比能量吸收（SEA）。虽然这些改进是以面外刚度、强度和SEA的部分降低为代价的，但IEH的面内性能达到了其面外性能的约70%，大大提高了结构的各向同性。引入层间间隔梯度会导致面外力学性能略有降低，同时提高冲击下的早期减速性能。这些发现促进了利用IEH芯材的夹芯板在需要增强多方向冲击抗性的应用中的巨大潜力。
