Bauer Jens, Kraus Julie A, Crook Cameron, Rimoli Julian J, Valdevit Lorenzo
Mechanical and Aerospace Engineering Department, University of California, Irvine, Irvine, CA, 92697, USA.
School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Adv Mater. 2021 Mar;33(10):e2005647. doi: 10.1002/adma.202005647. Epub 2021 Feb 5.
Failure of materials and structures is inherently linked to localized mechanisms, from shear banding in metals, to crack propagation in ceramics and collapse of space-trusses after buckling of individual struts. In lightweight structures, localized deformation causes catastrophic failure, limiting their application to small strain regimes. To ensure robustness under real-world nonlinear loading scenarios, overdesigned linear-elastic constructions are adopted. Here, the concept of delocalized deformation as a pathway to failure-resistant structures and materials is introduced. Space-tileable tensegrity metamaterials achieving delocalized deformation via the discontinuity of their compression members are presented. Unprecedented failure resistance is shown, with up to 25-fold enhancement in deformability and orders of magnitude increased energy absorption capability without failure over same-strength state-of-the-art lattice architectures. This study provides important groundwork for design of superior engineering systems, from reusable impact protection systems to adaptive load-bearing structures.
材料和结构的失效与局部机制有着内在联系，从金属中的剪切带，到陶瓷中的裂纹扩展，再到单个支柱屈曲后空间桁架的坍塌。在轻质结构中，局部变形会导致灾难性失效，将其应用限制在小应变范围内。为确保在实际非线性加载场景下的稳健性，采用了过度设计的线弹性结构。在此，引入了非局部变形的概念，作为实现抗失效结构和材料的途径。展示了通过其受压构件的不连续性实现非局部变形的可空间拼接张拉整体超材料。结果表明其具有前所未有的抗失效能力，在相同强度的现有晶格结构中，变形能力提高了25倍，能量吸收能力提高了几个数量级且无失效现象。这项研究为设计卓越的工程系统奠定了重要基础，从可重复使用的冲击保护系统到自适应承重结构。
