Fan Mu, Min Hequn
State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210010, China.
Key Laboratory of Urban and Architectural Heritage Conservation, Ministry of Education, School of Architecture, Southeast University, Nanjing 210096, China.
Materials (Basel). 2020 Apr 8;13(7):1735. doi: 10.3390/ma13071735.
Piezoelectric materials with the electro-mechanical coupling effect have been widely utilized in sensors, dampers, actuators, and so on. Engineering structures with piezoelectric actuators and sensors have provided great improvement in terms of vibration and noise reduction. The flexoelectric effect-which describes the coupling effect between the polarization gradient and strain, and between the strain gradient and electric polarization in solids-has a fourth-rank order tensor electro-mechanical coupling coefficient, and in principle makes the flexoelectricity existing in all insulating materials and promises an even wider application potential in vibration and noise control. In the presented work, a flexoelectric actuator was designed to actuate a simply supported beam. The electric field gradient was generated by an atomic force microscopy probe. Flexoelectric control force and moment components could be induced within the flexoelectric control layer. As flexoelectricity is size-dependent, the key parameters that could affect the actuating effect were examined in case studies. Analytical results showed that the induced flexoelectric control moment was strongly concentrated at the probe location. The controllable transverse displacement of the simply supported beam was calculated with the modal expansion method. It was found that the controllable transverse displacement was dependent on the probe location as well.
具有机电耦合效应的压电材料已广泛应用于传感器、阻尼器、致动器等。带有压电致动器和传感器的工程结构在振动和降噪方面有了很大改进。挠曲电效应——描述了固体中极化梯度与应变之间以及应变梯度与电极化之间的耦合效应——具有四阶张量机电耦合系数，并且原则上使得挠曲电存在于所有绝缘材料中，并有望在振动和噪声控制方面有更广泛的应用潜力。在本研究中，设计了一种挠曲电致动器来驱动简支梁。电场梯度由原子力显微镜探针产生。挠曲电控制力和力矩分量可在挠曲电控制层内感应产生。由于挠曲电与尺寸有关，在案例研究中考察了可能影响驱动效果的关键参数。分析结果表明，感应挠曲电控制力矩强烈集中在探针位置。用模态展开法计算了简支梁的可控横向位移。发现可控横向位移也取决于探针位置。
