Xing Yun, Yang Can, Sun Shu-Yi, Zhao Zi-Long, Feng Xi-Qiao, Yang Jialing, Gao Huajian
Institute of Solid Mechanics, School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, PR China; School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, Singapore 639798, Singapore; Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, PR China.
Institute of Solid Mechanics, School of Aeronautic Science and Engineering, Beihang University, Beijing 100191, PR China.
Acta Biomater. 2025 Jan 15;192:90-100. doi: 10.1016/j.actbio.2024.12.013. Epub 2024 Dec 5.
Biological materials, such as beetle elytra and bird beaks, exhibit complex interfaces with diverse morphologies that have evolved to enhance their mechanical properties. However, the relationships between their geometric forms and mechanical properties remain inadequately understood. Here, we develop a theoretical model, supported by finite element simulations and experiments, to explore the strengthening and toughening mechanisms of biological interfaces characterized by elliptical interlocking sutures. We examine how aspect ratio, interlocking angle, and friction influence the stiffness, strength, and toughness (defined as the area under the stress-strain curve) of these interfaces. A phase diagram is presented to analyze the typical failure modes of sutured interfaces. We discuss the mechanistic advantages of various elliptical suture designs and demonstrate that the optimal aspect ratio and interlocking angle predicted by our model correspond closely with those observed in beetle elytra. This study advances our understanding of the mechanical principles governing biological sutured interfaces and provides valuable insights for the design of engineering joints, interlocking structures, and protective systems. STATEMENT OF SIGNIFICANCE: Biological interfaces characterized by elliptical interlocking sutures exist widely in nature. They exhibit superior mechanical properties and efficient biological functions. Here, we develop a theoretical model to explore their strengthening and toughening mechanisms. We reveal the effects of aspect ratio, interlocking angle, and friction of the interfaces on their load-bearing capability, deformability, and failure mechanisms. The failure modes of the sutured interfaces are deciphered and their mechanistic advantages are uncovered. The mechanically optimal suture geometries predicted by our theoretical model align with those in beetle elytra. This work deepens our understanding of the structure-property interrelations of biological sutured interfaces. The obtained results hold a promise in the design of, e.g., engineering joints, interlocking structures, and protective systems.
生物材料，如甲虫鞘翅和鸟喙，呈现出具有多样形态的复杂界面，这些界面经过进化以增强其机械性能。然而，它们的几何形状与机械性能之间的关系仍未得到充分理解。在此，我们开发了一个理论模型，并辅以有限元模拟和实验，以探究以椭圆形互锁缝线为特征的生物界面的强化和增韧机制。我们研究了纵横比、互锁角度和摩擦力如何影响这些界面的刚度、强度和韧性（定义为应力 - 应变曲线下的面积）。给出了一个相图来分析缝合界面的典型失效模式。我们讨论了各种椭圆形缝线设计的机械优势，并证明我们模型预测的最佳纵横比和互锁角度与在甲虫鞘翅中观察到的非常接近。这项研究推进了我们对生物缝合界面力学原理的理解，并为工程接头、互锁结构和防护系统的设计提供了有价值的见解。重要性声明：以椭圆形互锁缝线为特征的生物界面在自然界广泛存在。它们表现出卓越的机械性能和高效的生物功能。在此，我们开发了一个理论模型来探究它们的强化和增韧机制。我们揭示了界面的纵横比、互锁角度和摩擦力对其承载能力、变形能力和失效机制的影响。解读了缝合界面的失效模式并揭示了它们的机械优势。我们理论模型预测的机械最优缝线几何形状与甲虫鞘翅中的一致。这项工作加深了我们对生物缝合界面结构 - 性能相互关系的理解。所得结果在例如工程接头、互锁结构和防护系统的设计中具有前景。
