高频换能器功率疲劳分析

压电陶瓷元件因疲劳破坏而失效是造成高频发射换能器损坏的重要原因之一。以一款高频换能器为例分析了换能器功率疲劳现象和压电陶瓷功率疲劳机理;针对高频换能器水中阻抗与空气中阻抗比较接近的特点,设计了空气中大功率发射以加速复现功率疲劳的实验方法,制作了实验样机;实验较好地复现了电导值下降、发送电压响应下降的功率疲劳故障现象,验证了发射功率是换能器功率疲劳的主要因素。当发射功率较大时,散热环境是诱发功率疲劳的重要因素。为避免换能器产生功率疲劳,必须重视发射功率、工作环境和散热情况;发射功率越大对工作环境散热要求越高。

Research on the power fatigue problem of high frequency underwater transducer

The piezoelectric ceramics invalidation caused by fatigue damage is one of the most important problems which results in transducer array inefficacy. The power fatigue phenomenon and piezoelectric ceramics power fatigue mechanism of a typical high-frequency transducer has been analyzed in this paper. Since the characteristic that the impedance of high frequency transducer in the air is close to that in the water, the high-power transmission repeated in air has been designed to speed up the launch of fatigue and the experimental prototype has also been made. Experiment recreates the power fatigue failure including conductance value falls and declining of sending voltage response. The results show that transmitting power is the main factor of transducer power fatigue; heat loss state is also a important factor. To avoid transducer power fatigue, more attention must be paid to transmitting power and heat loss state. The requirement of heat dissipation depends on the level of transmission power.