Two innovative re-entrant hierarchical sandwich panels constructed by substituting the cell walls of re-entrant honeycombs with isotropic regular hexagon substructure (RHH) and equilateral triangle substructure (RHT) are proposed in this paper, and their crashworthiness performance has been investigated systematically. Based on the Euler beam theory, the Young's moduli of units of re-entrant hierarchical sandwich panels are derived. A comparison between the re-entrant hierarchical sandwich panels and re-entrant sandwich panel has been conducted to study their energy absorption ability. Furthermore, the parametric analysis based on numerical analysis has been carried out to discuss the effects of the gradient, arranged orientation of hierarchical sandwich cores and the impact velocities. Results show that both the two proposed sandwich panels can greatly improve the in-plane stiffness and the energy absorption capacity, and the energy absorption mechanisms are discussed. In addition, the graded sandwich panels can effectively reduce initial peak force under quasi-static compression, and the configuration of large- medium -small (LMS) performs the best under high impact velocity. The cross-arranged cores can significantly improve the impact resistance ability of RHT sandwich panels. This work provides a new solution for designing lightweight sandwich structures.

本文提出了两种创新的凹入式分层夹心板，分别用各向同性的正六边形子结构（RHH）和等边三角形的子结构（RHT）替代凹入的蜂窝结构，并对它们的耐撞性能进行了系统的研究。基于欧拉梁理论，推导了折返式分层夹心板单元的杨氏模量。对折返式分层夹心板和折返式夹心板进行了比较，以研究其能量吸收能力。此外，已经进行了基于数值分析的参数分析，以讨论梯度的影响，分层夹芯的排列方向以及冲击速度。结果表明，所提出的两种夹心板都可以大大提高面内刚度和能量吸收能力，并讨论了能量吸收机理。此外，渐变夹层板可有效降低准静态压缩下的初始峰值力，大中小（LMS）的配置在高冲击速度下表现最佳。交叉排列的芯可以显着提高RHT夹心板的抗冲击能力。这项工作为设计轻质夹层结构提供了新的解决方案。大中小（LMS）的配置在高冲击速度下表现最佳。交叉排列的芯可以显着提高RHT夹心板的抗冲击能力。这项工作为设计轻质夹层结构提供了新的解决方案。大中小（LMS）的配置在高冲击速度下表现最佳。交叉排列的芯可以显着提高RHT夹心板的抗冲击能力。这项工作为设计轻质夹层结构提供了新的解决方案。