Piezoelectric bionic fishtails have good flexibility, response speed, anti-interference ability, and have great application prospects in ocean exploration. However, the inherent drawbacks of the mechanical properties of traditional homogeneous piezoelectric materials significantly affect the propulsion performance and reliability of the piezoelectric bionic fishtails. To fill this gap, this paper develops a functionally graded piezoelectric bionic fishtail (FGPBF) by imitating the tail characteristics of groupers. The geometric structure and working principle of the FGPBF are introduced in detail. Based on the first-order shear deformation theory and Hermite element-free method, an element-free model for the FGPBF is established. The effects of gradient factor, substrate material, substrate thickness and electrical load on the propulsion performance of the FGPBF are addressed. The results show that the current results are in good agreement with the finite element results. The deformation of the FGPBF is negatively correlated with the thickness and stiffness of the substrate and linearly positively correlated with the electrical load. As the gradient factor increases, the deflection of the FGPBF first increases and then decreases. When the gradient factor is 2, the potential is 200 V, the dimensionless aluminum substrate thickness is 1, the propulsion performance of the FGPBF is improved by 28% compared to the homogeneous piezoelectric bionic fishtail.

中文翻译：

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基于Hermite无单元法的功能梯度压电仿生鱼尾数值分析

压电仿生鱼尾具有良好的灵活性、响应速度、抗干扰能力，在海洋探索中具有巨大的应用前景。然而，传统均质压电材料力学性能的固有缺陷严重影响了压电仿生鱼尾的推进性能和可靠性。为了填补这一空白，本文通过模仿石斑鱼的尾部特征，开发了一种功能梯度压电仿生鱼尾（FGPBF）。详细介绍了FGPBF的几何结构和工作原理。基于一阶剪切变形理论和Hermite无单元方法，建立了FGPBF无单元模型。讨论了梯度因子、基底材料、基底厚度和电负载对 FGPBF 推进性能的影响。结果表明，当前的结果与有限元结果吻合较好。 FGPBF的变形与基板的厚度和刚度负相关，与电负载线性正相关。随着梯度因子的增大，FGPBF的偏转先增大后减小。当梯度因子为2、电位为200 V、无量纲铝基板厚度为1时，FGPBF的推进性能较均质压电仿生鱼尾提高了28%。