An important problem in transducer design is the accurate determination of electromechanical coupling coefficients for piezoelectric materials. The authors report on novel methods for determining both k/sub t/ the thickness mode coefficient, and k/sub 31/, an important parameter for transducer arrays. The coupling coefficients are computed near piezoelectric resonances using Krimholtz-Leedom-Matthaei (KLM) equivalent circuit models. These models have been modified to account for the mechanical losses of the material through an effective attenuation coefficient which can be estimated independently of the coupling coefficient. This measurement theory is applied to three different transducer materials: PVDF (polyvinylidene fluoride), PZT5A and a PZT (lead zinc titanate)/epoxy composite.
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机译:传感器设计中的一个重要问题是压电材料机电耦合系数的准确确定。作者报告了用于确定k / sum t /厚度模式系数和k / sub 31 /,换能器阵列的重要参数的新方法。使用Krimholtz-Leedom-Matthaei(KLM)等效电路模型来计算耦合系数附近压电谐振。已经修改这些模型以通过有效衰减系数来解释材料的机械损耗,这可以通过耦合系数独立地估计。该测量理论应用于三种不同的换能器材料:PVDF(聚偏二氟乙烯),PZT5a和PZT(钛酸锌)/环氧复合材料。
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