声波测井压电振子的有限元分析  

The finite element analysis of a piezoelectric bender used in acoustic logging

作　　者：吴金平[1,2] 乔文孝[1,2] 车小花[1,2] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]北京市地球探测与信息技术重点实验室,北京102249

出　　处：《应用声学》2012年第2期86-92,共7页Journal of Applied Acoustics

基　　金：国家自然科学基金面上项目(40874097);国家科技重大专项(2011ZX05020-009)的资助

摘　　要：压电振子是新一代方位声波测井仪器中相控圆弧阵声波辐射器的重要组成部分。利用有限元法对构成圆弧阵的压电振子进行了设计分析,结果显示了压电振子存在多阶弯曲振动模态,且长度方向一阶弯曲振动能够满足方位声波测井的工作频率要求。针对长度方向一阶弯曲振动模式,数值模拟了几何尺寸对压电振子性能参数的影响。压电振子的谐振频率随着陶瓷片长度、基片或陶瓷片厚度的减小而降低;压电振子的辐射声功率随着陶瓷片长度或压电振子宽度的增加、基片或陶瓷片厚度的减小而增大;合理地选取长度和厚度可使压电振子具有较高的机电耦合系数。数值模拟结果可以对圆弧阵结构优化设计起到良好的指导作用。Piezoelectric benders are important parts of acoustic phased arc array transmitter used in the latest generation of azimuth acoustic logging tools. Piezoelectric bender which is employed to form arc array transmitter is designed and analyzed applying a finite element method. The results show that the bender has abundant bending vibration modes and the resonance frequency of the first longitudinal bending vibration mode meets the operating frequency requirement for azimuth acoustic logging. Aimed at this first mode, the influence of geometric factors of piezoelectric bender on performance parameters is also simulated numerically. The resonance frequency will reduce as the length of ceramic plates, the thickness of the substrate or ceramic plates decreases. The radiation sound power will improve as the length of ceramic plates or the width of the bender increases, and as the thickness of the substrate or ceramic plates decreases. The bender with higher electromechanical coupling factor can be designed by choosing its length and thickness correctly. Numerical simulation results play a good guidance role on the structural optimization design for arc array transmitter.

关 键 词：压电振子 振动模式 谐振频率 有效机电耦合系数 

分 类 号：P631.52[天文地球—地质矿产勘探] O429[天文地球—地质学]