In the past two decades, thin lead zirconate titanate (PZT) sensors have been widely used in the electro-mechanical impedance (EMI) technique for sensing applications, particularly for monitoring civil structures. They are typically surface bonded using an industrial adhesive to the monitored structure. The bond between a PZT sensor and structure must be sufficiently strong to transmit the response of the structure to the sensor. In this study, acrylic cubes bonded with PZT patches are subjected to high compressive strains above 2000 με to develop a better understanding of bonding conditions when structures undergo such high strains. Acrylic can undergo such high strains without developing fissures or cracks. Thus, the recorded EMI response only reflects changes in the bonding condition due to the development of strains. The experiments are also numerically supplemented by simulating various debonding conditions. At higher strains, it was observed that the admittance signatures tend to behave similarly to a freely vibrating PZT patch, indicating debonding around the periphery. Even after the complete unloading of the structure, the signatures did not return to their initial state, indicating a permanent partial debonding. The strains developed on a loaded structure are not uniform and can be localized due to structural imperfections, resulting in higher strains in the region where a sensor is bonded. The insights from this study will aid in expanding the scope of the application of PZT sensors for monitoring civil structures through better comprehension of the PZT-structure bond under high compressive strains.

中文翻译：

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结构高压缩应变下压电传感器粘合条件的实验和数值研究

在过去的二十年中，薄锆钛酸铅 (PZT) 传感器已广泛用于传感应用的机电阻抗 (EMI) 技术，特别是用于监测土木结构。它们通常使用工业粘合剂表面粘合到受监控的结构上。PZT 传感器和结构之间的结合必须足够牢固，才能将结构的响应传输到传感器。在这项研究中，与 PZT 贴片粘合的丙烯酸立方体承受超过 2000 με 的高压缩应变，以便更好地了解结构承受如此高应变时的粘合条件。丙烯酸可以承受如此高的应变而不会产生裂缝或裂纹。因此，记录的 EMI 响应仅反映由于应变的发展而导致的粘合条件的变化。实验还通过模拟各种脱粘条件对实验进行了数值补充。在较高应变下，观察到导纳特征往往与自由振动的 PZT 贴片表现相似，表明周边发生脱粘。即使在结构完全卸载之后，签名也没有返回到其初始状态，这表明永久的部分脱粘。负载结构上产生的应变不均匀，并且可能由于结构缺陷而局部化，从而导致传感器粘合区域产生更高的应变。这项研究的见解将有助于通过更好地理解高压缩应变下 PZT 结构粘合来扩大 PZT 传感器在监测土木结构方面的应用范围。