论文标题
拓扑麦克斯韦超材料的压力聚焦和损害保护
Stress focusing and damage protection in topological Maxwell metamaterials
论文作者
论文摘要
拓扑机制领域的进步突出了麦克斯韦晶格的许多特殊机械特性,包括能够将零能量软盘模式和自我压力状态(SSS)的能力集中在其边缘和界面上。由于其拓扑特征,这些现象受到晶格几何和材料特性中的扰动的保护,这使它们与结构性非理想性,缺陷和损害的出现有关。最近的计算工作表明,可以利用麦克斯韦晶格沿规定的SSS域壁将应力聚焦到应力的能力,目的是为了保护大部分晶格中的其他区域免受有害的应力浓度,并可能抑制诸如孔和裂缝之类的压力热点处分裂机制的发作。该属性提供了一种强大的,基于几何形状的工具,用于设计具有损坏和断裂的晶格配置。在这项工作中,我们在现实的结构晶格的背景下,以非理想的有限厚度铰链为特征,对这一思想进行了全面的实验驱动探索。我们的实验记录了明显的域壁应力聚焦的发作,即使在结构铰链的稀释效应的情况下,极化也具有显着的鲁棒性。我们还证明了极化可以保护晶格免受散装中缺陷的铰链和裂纹的潜在故障。最后,我们从数值上说明了SSS域壁的优越性与其他琐碎形式的增援。
Advances in the field of topological mechanics have highlighted a number of special mechanical properties of Maxwell lattices, including the ability to focus zero-energy floppy modes and states of self-stress (SSS) at their edges and interfaces. Due to their topological character, these phenomena are protected against perturbations in the lattice geometry and material properties, which makes them robust against the emergence of structural non-idealities, defects, and damage. Recent computational work has shown that the ability of Maxwell lattices to focus stress along prescribed SSS domain walls can be harnessed for the purpose of protecting other regions in the bulk of the lattice from detrimental stress concentration and, potentially, inhibiting the onset of fracture mechanisms at stress hot spots such as holes and cracks. This property provides a powerful, geometry-based tool for the design of lattice configurations that are robust against damage and fracture. In this work, we provide a comprehensive experiment-driven exploration of this idea in the context of realistic structural lattices characterized by non-ideal, finite-thickness hinges. Our experiments document the onset of pronounced domain wall stress focusing, indicating a remarkable robustness of the polarization even in the presence of the dilutive effects of the structural hinges. We also demonstrate that the polarization protects the lattice against potential failure from defected hinges and cracks in the bulk. Finally, we illustrate numerically the superiority of SSS domain walls compared to other trivial forms of reinforcements.