【作者】 王艳红；

【导师】 刘金喜；

【作者基本信息】 石家庄铁道学院 ， 固体力学， 2008， 硕士

【摘要】 由于能够实现电能和机械能的相互转换,压电材料被广泛用于制作传感器、滤波器、换能器和执行器等各种压电装置。这些器件通常是层状的,而且他们的许多应用以弹性波的传播知识为理论基础。因此,压电层状结构中弹性波的传播性能一直是应用物理、力学和声学等领域内的重要研究内容。假定界面是非理想粘接的,本文研究了两种层状压电结构中的SH波传播问题,一种是平面层状的,另一种是层状复合柱体。压电材料具有横观各向同性的性能,而纯弹性材料是各向同性和正交各向异性的。对于所考虑的层状结构,推导了它们的频散方程,并对几种不同的材料组合计算了相速度随波数的变化规律。数值结果表明：(a)与理想界面比较,波数较小时,非理想界面降低了SH波传播的相速度；(b)当波数较小和界面较为理想时,压电层和纯弹性基底(或纯弹性柱)的厚度比越大,相应的相速度越小；(c)压电材料性能之间的差异对频散特性有显著的影响,而且其影响由压电材料B-G波或剪切体波的速度来反映；(d)对于正交各向异性层/压电半空间耦合结构,各向异性程度越高,相应的相速度越低。上述结果对改进层状压电结构在压电器件中的应用以及通过实验测定界面的性能具有参考价值。更多还原

【Abstract】 Due to the capability of conversion between mechanical and electrical energy, piezoelectric materials have widely been used in technology as sensors, filters, transducers and actuators, and so on. These devices are commonly constructed in layered form and many applications of them are related to the knowledge of elastic wave propagation. Therefore, studies of the propagation of elastic waves accompanied by electrical waves have long been of interesting to researchers in the fields of applied physics, mechanics and acoustics.This dissertation deals with the propagation of shear horizontal (SH) waves in two kinds of layered structures consisting of piezoelectric and purely elastic media:one being the plane layered structure, and the other being the layered cylinder. The interface is assumed to be imperfect. Piezoelectric materials are transversely isotropic, while pure elastic materials are isotropic or orthotropic.The dispersion equations for the considered layered structures are derived and then the phase velocities are calculated for different material combinations. The numerical results show that:(a) In comparison with the case of the perfect interface, the imperfect degree of the interface reduces the phase velocities at the lower wave number. (b) When the wave number is lower and the imperfect degree of the interface is weaker, the phase velocities decrease as the ratio of the thickness of the piezoelectric layer to the purely elastic substrate or cylinder increases. (c) The difference between piezoelectric material properties has substantial influences on the dispersion characteristics, and their influences are reflected by velocities of the B-G surface wave and SH bulk wave. (d) For the piezoelectric half-space carrying a purely elastic orthotropic layer, the phase velocity decrease with the increase of the anisotropic degree. These findings may useful for improvement of piezoelectric devices or structures as well the experimental determination of interface property.更多还原