Enhancing the operational range of piezoelectric actuators by uniaxial compressive preloading
Enhancing the operational range of piezoelectric actuators by uniaxial compressive preloading
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DOI：
10.1088/0022-3727/48/21/215302
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发表时间：
2015-06
期刊：
影响因子：
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通讯作者：
J. Koruza;D. J. Franzbach;F. H. Schader;Virginia Rojas;K. Webber
中科院分区：
文献类型：
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作者：
J. Koruza;D. J. Franzbach;F. H. Schader;Virginia Rojas;K. Webber
研究了单轴预加载对压电陶瓷非谐振驱动性能的影响，压缩预加载值高达-80 MPa。研究是在软型锆钛酸铅（PZT），是最广泛使用的压电材料。使用比例加载方法分析样品，该方法能够同时施加电负载和机械负载，从而在整个应力-应变范围内模拟真实的操作条件。对于所有施加的预载荷值，观察到阻塞应力和纵向压电应力系数的增加。在预载荷为−40 MPa和电场为2 kV mm − 1时，获得了最佳性能，即阻断应力为−56 MPa，自由应变为0.23%。与最小预载荷下获得的值相比，这分别表示增加了16%和20%。此外，最大工作输出增加了约28%。最后，将采用比例加载法在最低预载荷−4 MPa下获得的结果与其他方法确定的工作范围进行了比较。比较发现，这些方法之间存在很大的差异，源于电场和机械场的应用顺序不同以及铁电材料固有的非线性。由于阻抗失配，这种差异导致致动器性能降低，表明需要准确确定致动器的操作范围。
The influence of the uniaxial preload on the off-resonance actuation performance of piezoelectric ceramics was investigated for compressive preload values up to −80 MPa. The study was performed on soft-type lead zirconate titanate (PZT), being the most widely used piezoelectric material. The samples were analysed using the proportional loading method, which enables the simultaneous application of electrical and mechanical loads, thereby mimicking the real operation conditions over the full stress–strain range. An increase of the blocking stress and the longitudinal piezoelectric stress coefficient was observed for all the applied preload values. The optimum properties, a blocking stress of −56 MPa and a free strain of 0.23%, were obtained at a preload value of −40 MPa and electric field of 2 kV mm − 1. This represents an increase of 16% and 20%, respectively, as compared to the values obtained at the smallest preload. In addition, the maximum work output was increased by about 28%. Finally, the results obtained at the lowest preload of −4 MPa using the proportional loading method were compared to the operational ranges determined by other methods. The comparison revealed large discrepancies between the methods, originating from the different order of the application of electrical and mechanical fields and the inherent nonlinearity of ferroelectric materials. This discrepancy results in decreased actuator performance due to impedance mismatching, demonstrating the need for accurate determination of the actuator’s operational range.