Transient deformation and curvature evolution during the snap-through of a bistable laminate under asymmetric point load
Transient deformation and curvature evolution during the snap-through of a bistable laminate under asymmetric point load
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DOI：
10.1016/j.compscitech.2021.108871
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发表时间：
2021-05-24
影响因子：
9.1
通讯作者：
Li, Suyi
中科院分区：
文献类型：
--
作者：
Deshpande, Vishrut;Myers, Oliver;Li, Suyi
双稳态碳纤维复合材料，其双稳态性产生于具有不对称的纤维布局在不同的层，已显示出巨大的潜力，用于形状变形和自适应结构的应用。虽然该领域的许多研究都集中在这些复合材料层合板在两个稳定状态下的外部形状上，但它们从一个稳定形状转变到另一个稳定形状的突变行为仍然是一个需要详细研究的关键方面。此外，基于经典层合板理论，对称加载条件已经得到了广泛的研究，但非对称加载条件受到的关注要少得多。因此，本研究探讨了一个不对称的，局部的点载荷上的[0圆/90圆]层压板和其复杂的瞬态变形过程中的快速通过。有限元模拟和实验结果揭示了三种独特的不同的卡扣行为-两步卡扣，一步卡扣，和没有卡扣-取决于点载荷位置。从有限元和数字图像相关结果计算的“曲率反转区”的局部化起始和传播与这些快速通过特性直接相关。本研究也探讨了使用经典层压理论的扩展分析模型来定性重现上述发现的可行性。该模型比较了三种不同阶次的多项式函数来近似层合板的面外位移场。这项研究的结果可以为不同负载情况下双稳态复合材料的快速行为的基本机制和驱动设计提供有价值的见解。
Bistable carbon fiber composites, whose bistability arises from having asymmetric fiber layouts in different layers, have shown immense potential for using in shape morphing and adaptive structure applications. While many studies in this field focus on these composite laminates' external shapes at the two stable states, their snapthrough behavior of shifting from one stable shape to the other remains a critical aspect to be investigated in complete detail. Moreover, symmetric loading conditions have been extensively studied based on the classical lamination theory, but the asymmetric loading conditions received far less attention. Therefore, this study examines an asymmetric, localized point load on a [0 circle/90 circle] bistable laminate and its complex transient deformation during the snap-through. Finite element simulation and experiment results reveal three uniquely different snapthrough behaviors - two-step snap, one-step snap, and no snap - depending on the point load location. The localized initiation and propagation of a "curvature inversion zone," calculated from finite element and digital image correlation results, are directly related to these snap-through characteristics. This study also explored the feasibility of using an extended analytical model of classical lamination theory to qualitatively reproduce the above findings. This model compares three polynomial functions of different orders to approximate the out-ofplane laminate displacement field. This study's results can offer valuable insights into the fundamental mechanics of snap-through behaviors and the actuation designs for the bistable composites for different loading scenarios.