Bilgunde Prathamesh N, Bond Leonard J
Department of Aerospace Engineering, Iowa State University, USA.
Department of Aerospace Engineering, Iowa State University, USA; Center for NDE, Iowa State University,1915 Scholl Road, Ames, IA 50011, USA.
Ultrasonics. 2018 Jul;87:103-111. doi: 10.1016/j.ultras.2018.02.007. Epub 2018 Feb 9.
Ultrasonic transducers for high temperature (200 °C+) applications are a key enabling technology for advanced nuclear power systems and in a range of chemical and petro-chemical industries. Design, fabrication and optimization of such transducers using piezoelectric materials remains a challenge. In this work, experimental data-based analysis is performed to investigate the fundamental causal factors for the resonance characteristics of a piezoelectric disc at elevated temperatures. The effect of all ten temperature-dependent piezoelectric constants (ε, ε, d, d, d, s, s, s, s, s) is studied numerically on both the radial and thickness mode resonances of a piezoelectric disc. A sensitivity index is defined to quantify the effect of each of the temperature-dependent coefficients on the resonance modes of the modified lead zirconium titanate disc. The temperature dependence of s showed highest sensitivity towards the thickness resonance mode followed by ε, s, s, s, d, d, s, ε, and d in the decreasing order of the sensitivity index. For radial resonance modes, the temperature dependence of ε showed highest sensitivity index followed by s, s and d coefficient. This numerical study demonstrates that the magnitude of d is not the sole factor that affects the resonance characteristics of the piezoelectric disc at high temperatures. It appears that there exists a complex interplay between various temperature dependent piezoelectric coefficients that causes reduction in the thickness mode resonance frequencies which is found to be agreement in with the experimental data at an elevated temperature.
用于高温（200°C 以上）应用的超声换能器是先进核电系统以及一系列化学和石油化工行业的关键 enabling 技术。使用压电材料对这类换能器进行设计、制造和优化仍然是一项挑战。在这项工作中，基于实验数据进行分析，以研究高温下压电圆盘共振特性的基本因果因素。对十个与温度相关的压电常数（ε、ε、d、d、d、s、s、s、s、s）对压电圆盘径向和厚度模式共振的影响进行了数值研究。定义了一个灵敏度指数来量化每个与温度相关的系数对改性钛酸铅锆圆盘共振模式的影响。s 的温度依赖性对厚度共振模式显示出最高的灵敏度，其次是 ε、s、s、s、d、d、s、ε 和 d，按灵敏度指数降序排列。对于径向共振模式，ε 的温度依赖性显示出最高的灵敏度指数，其次是 s、s 和 d 系数。这项数值研究表明，d 的大小不是影响高温下压电圆盘共振特性的唯一因素。似乎各种与温度相关的压电系数之间存在复杂的相互作用，导致厚度模式共振频率降低，这与高温下的实验数据一致。
