论文标题
从扭曲的散装金属玻璃丝带中兼发的变形结构
Compliant morphing structures from twisted bulk metallic glass ribbons
论文作者
论文摘要
在这项工作中,我们研究了预搅打的金属丝带作为变形结构的基础。我们通过将其(纵向)质心轴的最初扁平丝带扭曲成螺旋形几何形状来制造这些元素,然后对它们进行热成型以使该构型成为无应力的参考状态。螺旋形形状使色带具有在其长度上变化的首选弯曲方向。这些弯曲方向用作合规的关节,并能够在没有前扭转的情况下进行几种部署和存放的配置,前提是压实不会引起材料故障。我们使用散装金属玻璃(BMG)制造这些丝带,以表彰其出色的弹性和热成型属性。通过基于壳理论和扭转实验的分析模型组合数值模拟,我们分析了各种色带几何形状的有限扭转力学。我们发现,在具有波动边缘的丝带中,可以在热成型之前更好地将扭曲变形局部定位在所需区域上。最后,我们将多丝带加在一起创建可部署的系统。我们的工作提出了一个框架,以创建完全金属但兼容的结构,这些结构可能会发现应用程序作为空间结构和合规机器人的元素。
In this work, we investigate the use of pre-twisted metallic ribbons as building blocks for shape-changing structures. We manufacture these elements by twisting initially flat ribbons about their (lengthwise) centroidal axis into a helicoidal geometry, then thermoforming them to make this configuration a stress-free reference state. The helicoidal shape allows the ribbon to have preferred bending directions that vary throughout its length. These bending directions serve as compliant joints and enable several deployed and stowed configurations that are unachievable without pre-twist, provided that compaction does not induce material failure. We fabricate these ribbons using a bulk metallic glass (BMG), for its exceptional elasticity and thermoforming attributes. Combining numerical simulations, an analytical model based on shell theory and torsional experiments, we analyze the finite-twisting mechanics of various ribbon geometries. We find that, in ribbons with undulated edges, the twisting deformations can be better localized onto desired regions prior to thermoforming. Finally, we join together multiple ribbons to create deployable systems. Our work proposes a framework for creating fully metallic, yet compliant structures that may find application as elements for space structures and compliant robots.