挠曲电效应对简支梁式压电传感器性能的影响

发布时间：2018-06-08 15:47

  本文选题：挠曲电效应 + 诱导电势　； 参考：《厦门大学学报(自然科学版)》2017年06期

【摘要】：挠曲电效应是材料极化强度(或电场强度)与应变梯度之间的耦合关系,对于新型微纳米致动器和传感器的性能具有重要的影响.以纳米简支梁式压电传感器(简称压电简支梁)为研究对象,讨论材料的挠曲电效应对压电简支梁输出电势与挠度的影响.采用电吉布斯自由能密度函数,并根据压电材料线性理论与伯努利-欧拉梁理论,采用变分法推导压电简支梁的控制方程和相应力电耦合边界条件.数值模拟BaTiO3压电简支梁在外加机械载荷作用下,由于挠曲电效应产生的诱导电势和极化强度等与梁结构、材料参数的相互关系.计算结果表明,诱导电势反馈作用在梁的表面引起一个与机械载荷作用相反的弯矩,减小了梁结构的弯曲挠度;在一定的挠曲电系数和梁结构尺寸下,诱导电势存在最大值;在微纳尺度上挠曲电效应具有很强的尺寸依赖性,随着梁的厚度增大,挠曲电效应的影响将显著减弱.
[Abstract]:The flexural effect is the coupling relationship between the polarization strength (or electric field intensity) and the strain gradient of the material, which has an important effect on the performance of the new micro and nano actuators and sensors. The effect of flexural electric effect on the output potential and deflection of piezoelectric simply supported beam is discussed in this paper. Based on the linear theory of piezoelectric materials and Bernoulli Euler beam theory, the control equation and the corresponding coupling boundary conditions of piezoelectric simply supported beam are derived by using the electric Gibbs free energy density function and the Bernoulli Euler beam theory. Numerical simulation of the relationship between the induced potential and polarization strength of a simply supported BaTiO3 piezoelectric beam under external mechanical loading and the structure of the beam is carried out. The results show that the induced potential feedback causes a bending moment opposite to the mechanical load on the surface of the beam, which reduces the bending deflection of the beam structure, and the induced potential has the maximum value under a certain flexural electric coefficient and the structure size of the beam. The flexural effect is highly dimensionally dependent on the micro- and nanoscale scale, and the effect of the flexoelectric effect decreases with the increase of the beam thickness.
【作者单位】： 厦门大学材料学院福建省特种先进材料重点实验室;集美大学诚毅学院;
【基金】：国家自然科学基金(11572271,11472233)
【分类号】：TP212
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本文编号：1996322