仿生柔性刺状阵列结构的缓冲特性及调控研究

To achieve the new requirements of impact protection for the human safety, this project propose a class of compliant spine-like array architectures, which is inspired by the semi-active protection of the spiny animals in nature. In the project, the cushioning performance and its tunability of the bio-inspired compliant spine-like array are studied. The content mainly includes three sections. In the section 1), the quasi-static and dynamic mechanical behavior and the cushioning performance of the compliant spine-like array are systematically studied by a combination of experiments and numerical simulations. And, the influence of structural parameters such as geometrical shape, geometric size, material properties, distribution density and arrangement of rods on its cushioning performance is revealed. In the section 2), the static and dynamic deformation modes and bearing capacity of the compliant spine-like arrays with different structural parameters are theoretically analyzed and the corresponding cushioning mechanisms are clarified. Also, the evaluation indexes of the cushioning performance of compliant spine-like arrays are developed in this section. In the section 3), the compliant spine-like array with the base structure in the form of pre-compression bi-stable beam is designed, based on the bearing characteristics of the negative Poisson's ratio structure. The buffering capacity is enhanced by the aggregation of the rods under larger impact load, and the purpose of bionic tunability of buffering capacity is achieved. Overall, this project is beneficial to promote protective applications of the compliant spine-like array in many fields such as aging health, sports, and aerospace.

在人体抗冲击防护装置新需求的牵引下，本项目受自然界多刺动物的半主动防护本领启发，提出一类仿生柔性刺状阵列防护结构，对其缓冲特性及缓冲能力调控方法展开研究。主要致力于：1）采用实验和数值模拟相结合的手段对柔性刺状阵列结构的整体静动态力学行为和缓冲能力进行系统研究，揭示阵列杆件几何形态、几何尺寸、材料属性、分布密度以及排布方式等结构特征参数对其缓冲性能的影响规律；2）理论分析不同结构形式柔性刺状阵列杆件的静动态变形模式和承载能力，阐明缓冲机理，给出柔性刺状阵列结构的缓冲能力评价指标；3）基于负泊松比结构的承压特性，设计预压双稳态梁基底构型的柔性刺状阵列结构，通过大冲击载荷下杆件的聚合来增强其缓冲能力，达到了缓冲能力仿生调控的目的。研究成果有助于推动该柔性刺状阵列结构在老龄健康、体育运动、航空航天等众多领域内的人体防护应用。

当前，我国老龄健康、体育运动、航空航天、防恐防暴等众多领域均对人体抗冲击安全防护需求。为此，本项目在自然界动植物优异的半主动防护本领启发下：设计了一类以极小曲面形态为主的仿生柔性阵列防护结构并进行了粉末烧结3D打印制备，采用实验和数值模拟相结合的手段对该TPU阵列结构的整体超弹性力学行为和能量吸收特性进行了细致的研究，考察了几何形态、几何尺寸、材料属性、分布壁厚以及排布方式等结构特征参数对其力学行为及缓冲性能的影响，发现了它们各自的压溃模式和变形规律；进一步，将单纯的柔性阵列结构扩展至柔性-硬质双相刺状互锁阵列结构，设计了仿龟壳、仿贝壳、仿甲壳虫式刺状互锁复合平板阵列 结构，然后采用PolyJet 3D打印技术制备了这些仿生抗冲击复合结构板，通过不同速度下的落锤冲击实验，研究了三类仿生结构以及对照结构的抗冲击响应特性及失效模式，深入探究了铺层角度和刺状形态维度对结构抗冲击性能的影响，并利用裂纹扩展失效理论揭示了铺层角度和刺状形态维度通过裂纹偏转实现增强结构抗冲击防护性能的内在机制。此外，还将上述仿生柔性阵列结构应用于人体跌倒防护装置和伞兵着陆缓冲靴的鞋底结构，通过准静态压缩、落锤冲击、人体跳跃实验以及数值模拟相结合的方法分析了不同几何形态柔性阵列结构的缓冲效果并进行了优选，结果表明所设计的柔性阵列缓冲鞋底能够使跳跃着陆人员在多种高度下着陆时地面峰值反力降低15%以上，体现出仿生柔性阵列结构在人体着陆缓冲方面的应用潜力。综上，该研究成果能够为基于仿生柔性阵列结构在人体抗冲击安全防护领域的应用提供理论依据和技术储备。