挠曲电超材料的拓扑优化及其表观压电性
Topology optimization of flexoelectric metamaterials with apparent piezoelectricity
AI总结：
本文通过拓扑优化设计非压电基材超材料，利用挠曲电效应实现表观压电性，并与石英和PZT陶瓷性能相当，为传感、致动和能量收集提供更广泛材料选择。
摘要：
挠曲电效应将极化与应变梯度以及应变与电场梯度耦合，对电介质具有普遍性，但与压电效应相比，它更难以利用，因为它需要场梯度且是一种小尺度效应。这些缺点可以通过适当设计由非压电基材制成但表现出表观压电性的超材料来克服。我们开发了一个理论和计算框架，通过使用笛卡尔B样条方法精确建模挠曲电性的控制方程、用水平集描述几何形状，并采用遗传算法进行优化，来对此类超材料的代表体积单元进行拓扑优化。我们考虑了一个多目标优化问题，其中面积分数与四种基本压电功能（应力/应变传感器/致动器）相互竞争。我们通过计算获得了帕累托前沿，并根据被优化的表观压电系数讨论了不同的几何形状。总体而言，我们发现与石英和PZT陶瓷等参考材料相比，表观压电性的估计具有竞争力。这为从更广泛、更便宜且有效的材料类别中设计用于传感、致动和能量收集的器件开辟了可能性。
英文摘要：
The flexoelectric effect, coupling polarization and strain gradient as well as strain and electric field gradients, is universal to dielectrics, but, as compared to piezoelectricity, it is more difficult to harness as it requires field gradients and it is a small-scale effect. These drawbacks can be overcome by suitably designing metamaterials made of a non-piezoelectric base material but exhibiting apparent piezoelectricity. We develop a theoretical and computational framework to perform topology optimization of the representative volume element of such metamaterials by accurately modeling the governing equations of flexoelectricity using a Cartesian B-spline method, describing geometry with a level set, and resorting to genetic algorithms for optimization. We consider a multi-objective optimization problem where area fraction competes with four fundamental piezoelectric functionalities (stress/strain sensor/ actuator). We computationally obtain Pareto fronts, and discuss the different geometries depending on the apparent piezoelectric coefficient being optimized. In general, we find competitive estimations of apparent piezoelectricity as compared to reference materials such as quartz and PZT ceramics. This opens the possibility to design devices for sensing, actuation and energy harvesting from a much wider, cheaper and effective class of materials.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
