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本文介绍四种压电陶瓷在电场激励下,其机械输出时的波形失真情况,在不同频率及不同电场下进行了测试。实验表明,以 P-8材料的波形失真为最小,本文并从压电陶瓷的应变-电场关系非线性来解释这一现象。一、问题的提出压电转换器根据其承受负载的状况,可分为功率转换器及振幅转换器两大类。功率转换器所承受的声负载较大,如在水中发射平面波时,其声阻抗可达1.5×10~6公斤/米~2·秒。这种转换器所追求的机声效率可达80～90%。而振幅转换器所承受的声负载较小,如在振动领域中所使用的压电激振器及压电传感器。此外,如超声切割机、超声薄膜焊接机、超声外科手术刀,都属此类情况,这种转换器所追求的机电转换效率是 A~2S/W(A 为振幅;S 为输出面积:W为输入总功率)和最大振幅 A_(max)。转换器使用状态也不同。有的是在谐振状态下使用,有的是在非谐振状态下使用。对做仪器用的振幅转换器。往往要求它在电场
In this paper, we introduce the waveform distortion of four kinds of piezoelectric ceramics under the electric field excitation under mechanical excitation, and carry on the test under different electric fields and frequencies. Experiments show that the waveform distortion of P-8 material is the minimum. This phenomenon is explained in this paper from the nonlinear strain-electric field relationship of piezoelectric ceramics. First, the problem presented Piezoelectric converters according to their load conditions, can be divided into two categories of power converters and amplitude converters. The power converter is subjected to a large acoustic load, such as acoustic impedance up to 1.5 × 10 ~ 6 kg / m ~ 2 · sec when launching plane waves in water. The pursuit of this converter sound efficiency up to 80 ~ 90%. The amplitude converter is subjected to less acoustic loads, such as the piezoelectric vibrators and piezoelectric sensors used in the vibration field. In addition, such as ultrasonic cutting machine, ultrasonic thin film welding machine, ultrasonic surgical scalpel, are of such cases, the pursuit of electromechanical converter efficiency is A ~ 2S / W (A amplitude; S output area: W For the total input power) and the maximum amplitude A_ (max). The converter status is also different. Some are used in the resonant state, some in the non-resonant state. Amplifier to do with the instrument. Often ask it in the electric field