Bristol Composites Institute (ACCIS), University of Bristol, BS8 1TR Bristol, United Kingdom.
School of Cellular and Molecular Medicine, University of Bristol, BS8 1TD Bristol, United Kingdom.
Bioinspir Biomim. 2020 Dec 24;16(2). doi: 10.1088/1748-3190/abc1f2.
Cactus fibres have previously shown unusual mechanical properties in terms of bending and axial stiffness due to their hierarchical structural morphology. Bioinspiration from those cactus fibres could potentially generate architected materials with exciting properties. To that end we have built bioinspired artificial analogues of cactus fibres to evaluate their mechanical properties. We have generated 3D printed specimens from rendered models of the cactus structure using two different printing techniques to assess the reproducibility of the structural topology. Bioinspired additive manufactured materials with unusual mechanical properties constitute an ever-evolving field for applications ranging from novel wing designs to lightweight plant-inspired analogues. The cactus-inspired 3D printed specimens developed here demonstrate an unusually high bending to axial stiffness ratios regardless of the manufacturing method used. Moreover, when compared to their equivalent beam analogues the cactus specimens demonstrate a significant potential in terms of specific (weight averaged) flexural modulus. Imaging of the artificial cactus reinforcements has enabled the generation of a one-dimensional reduced order finite element model of the cactus structure, with a distribution of cross sections along the length that simulate the inertia and mechanical behaviour of the cactus topology. The novel bioinspired material structure shows an excellent reproducibility across different manufacturing methods and suggest that the tree-like topology of the cactus fibre could be very suited to applications where high bending to axial stiffness ratios are critical.
仙人掌纤维由于其分级结构形态，在弯曲和轴向刚度方面表现出了异常的力学性能。这些仙人掌纤维的仿生学灵感可能会产生具有令人兴奋特性的结构材料。为此，我们构建了仙人掌纤维的仿生人工模拟物来评估它们的机械性能。我们使用两种不同的打印技术，从仙人掌结构的渲染模型生成了 3D 打印样本，以评估结构拓扑的可重复性。具有异常力学性能的仿生增材制造材料是一个不断发展的领域，其应用范围从新型机翼设计到轻质植物仿生模拟物。这里开发的仙人掌启发的 3D 打印样本无论使用哪种制造方法，都表现出了异常高的弯曲到轴向刚度比。此外，与等效的梁模拟物相比，仙人掌样本在特定（重量平均）弯曲模量方面表现出了显著的潜力。对人造仙人掌增强材料的成像使我们能够生成仙人掌结构的一维降阶有限元模型，其中沿着长度分布的横截面模拟了仙人掌拓扑的惯性和力学行为。新型仿生材料结构在不同制造方法之间具有出色的可重复性，并表明仙人掌纤维的树状拓扑结构非常适合对弯曲到轴向刚度比要求较高的应用。
