生物轻质高强结构及其在吸能结构中的仿生应用

在长期进化过程中,自然界中的多种动物、植物形成了独特的轻质、高强结构,以此来抵抗外界的复杂冲击载荷,保护自身完整,满足生存需要。生物轻质高强结构的优越性,启发了科研和工程人员采用结构仿生学的方法来对管状和板状两大类吸能结构进行设计优化和改进。对竹子、茎秆/树干、羽轴、骨骼四类管状生物结构和甲虫鞘翅、贝壳、柚子皮、龟壳四类板状生物结构进行综述,阐述了分层、多孔、螺旋、中空等多种结构与轻质高强特性之间的关系。在此基础上,对比和分析了相应的结构元素在单胞管、多胞管、嵌套管、波纹管等管状吸能结构和蜂窝夹芯板、复合材料板、混合结构板等板状吸能机构中起到的作用。进一步对当前仿生吸能领域存在的结构复杂、质量大、缺乏普适性的机理和过渡“桥梁”等问题做出了分析;最后对仿生吸能技术的形式简单化、结构轻量化、理论通用化、“形神兼备”化发展趋势做出展望。

Bio-lightweight and High Strength Structures and Their Bionic Applications in Energy Absorption Structures

In the process of long-term evolution, various animals and plants in nature have formed unique lightweight and high-strength structures to resist complex impact loads from the surroundings, protect their integrity, and meet the needs of survival. The advantages of bio-lightweight and high-strength structures have inspired researchers and engineers to use the method of structural bionics to optimize and improve the tubular and plate-like energy absorption structures. Four kinds of tubular biological structures of bamboo, stem/trunk, feather rachis and bone, and four kinds of plate-like biological structures of beetle elytra, shell, pomelo skin and tortoise shell are reviewed. The relationship between layered, porous, spiral and hollow structures and mechanical properties is described. On this basis, the effects of the corresponding structural elements on the tubular energy absorption structures such as single cell tube, multi-cell tube, nested tube and corrugated tube and the plate-like energy absorption structures such as honeycomb sandwich plate, composite plate and mixed structure plate are compared and analyzed. Further, the existing problems in the field of bionic energy absorption, such as complex structure, large mass, lack of universal mechanism and transition "bridge" are analyzed. Finally, the development trend of bionic energy absorption technology with simplified form, lightweight structure, universal theory and "both form and spirit" is prospected.