Abstract Bilayer piezo macro fiber composites (MFCs) with specific fiber orientations are experimentally known to undergo bending as well as twisting, under the action of an externally applied electric field. An analytical model is developed for this shape-morphing phenomenon using continuum mechanics and energy minimization considering material anisotropy. A detailed parametric study is carried out using a coupled electro-mechanical finite element model and the results are used to validate the analytical model. The analytical model quantitatively predicts the variation of curvatures with the system parameters (bilayer geometry and electric field magnitude) with good accuracy. The tendency of a bilayer to undergo pure bending, pure twisting or a helical deformation is predicted using stress-free strain mismatch between anisotropic layers. Both bending and twisting deformations are found to be strongly dependent on the fiber orientation, vary linearly with the applied electric field magnitude, independent of length and decrease with an increase in width or thickness of MFC.

中文翻译：

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压电复合材料中通过组合弯曲和扭曲变形的分析模型

摘要 具有特定纤维取向的双层压电大纤维复合材料 (MFC) 在外加电场的作用下会发生弯曲和扭曲。考虑到材料各向异性，使用连续介质力学和能量最小化为这种形状变形现象开发了一个分析模型。使用耦合机电有限元模型进行了详细的参数研究，结果用于验证分析模型。分析模型以良好的精度定量预测曲率随系统参数（双层几何结构和电场强度）的变化。使用各向异性层之间的无应力应变失配预测双层经历纯弯曲、纯扭曲或螺旋变形的趋势。