ABSTRACT

As a result of technological escalation in sensing applications, piezopolymers like Polyvinylidene fluoride (PVDF), very flexible in nature, are preferred over most of the piezoceramics which are stiff and brittle. PVDF, which is a Piezoelectric-Orthotropic material with a higher anisotropy, is frequently used in sensing devices for structural health monitoring and repairing. In the present analysis reflection phenomenon of plane wave incident at the boundary surface of the Rotating Functionally graded Initially stressed Piezoelectric-Orthotropic (RFIPO) half-space has been analyzed. The influence of Horizontal Normal Compressive Initial-stress (HNCIS); Tensile Shear Stress (TSS), and Vertical Normal Compressive Initial-stress (VNCIS) has been examined on Reflection Coefficients (RCs) of reflected qP, qSV, and EA-waves. Furthermore, the impacts of rotation and functional-gradient are analyzed extensively. Moreover, this phenomenon in the undertaken model has been compared with the model where half-space comprised of Rotating Functionally graded Initially stressed Transversely-isotropic Piezoelectric (RFITP) material. The deduced closed-form expression of RCs of reflected waves has been validated in view of law of conservation of energy and condition of grazing incidence of qP-wave. The comparative analysis of various cases concerned with RFIPO half-space and RFITP half-space serves as the key feature.

摘要

由于传感应用技术不断升级，像聚偏二氟乙烯 (PVDF) 这样的压电聚合物本质上非常柔韧，因此比大多数又硬又脆的压电陶瓷更受青睐。PVDF 是一种具有较高各向异性的压电正交各向异性材料，常用于结构健康监测和修复的传感装置。在本分析中，分析了平面波入射在旋转功能梯度初始应力压电正交各向异性（RFIPO）半空间的边界表面的反射现象。水平法向压缩初始应力（HNCIS）的影响；拉伸剪切应力 (TSS) 和垂直法向压缩初始应力 (VNCIS) 已在反射 qP、qSV 和 EA 波的反射系数 (RC) 上进行了检查。此外，旋转和功能梯度的影响被广泛分析。此外，所采用模型中的这种现象与半空间由旋转功能梯度初始应力横向各向同性压电（RFITP）材料组成的模型进行了比较。结合能量守恒定律和qP波掠入射条件，验证了推导的反射波RC闭式表达式。对涉及RFIPO半空间和RFITP半空间的各种案例的比较分析是关键特征。结合能量守恒定律和qP波掠入射条件，验证了推导的反射波RC闭式表达式。对涉及RFIPO半空间和RFITP半空间的各种案例的比较分析是关键特征。结合能量守恒定律和qP波掠入射条件，验证了推导的反射波RC闭式表达式。对涉及RFIPO半空间和RFITP半空间的各种案例的比较分析是关键特征。