中文摘要：

提出一种新型的施加预应力套叠圆管换能器。通过同轴紧密套叠粘接两压电陶瓷圆管,并在圆管外表面施加预应力构成换能器振子,以实现两管的径向振动叠加,达到提高圆管换能器的发送响应的目的。实验共制作了5只换能器,对其性能进行了测试。测试结果表明：套叠圆管换能器的发送响应较单管的提高了近7 d B左右,但对换能器的接收灵敏度无改善作用;套叠圆管施加预应力后,对发送响应和灵敏度均无改善作用。

英文摘要：

A new type of piezoelectric nested cylindrical transducer is put forward. The vibrator of the transducer is composed of two piezoelectric ceramic tubes which are bonded together closely. And the external surface of the piezoelectric ceramic tube is applied to the pre-stress. This structure can realize the superposition of radial vibration of two piezoelectric ceramic tubes. At the same time,the purpose of improving the transmitting sound level of the circular tube transducer is achieved. Experiments are made for 5 transducers. And the performance of the 5 transducer is tested exactly and analyzed carefully. The research suggests that compared with the ordinary single cylindrical,transmitting sound level of the piezoelectric nested cylindrical transducer increases nearly 7d B. But this new structure has little effect on the sensitivity of the transducer. After applying pre-stress on the vibrator of piezoelectric nested cylindrical transducer,neither the transmitting sound level nor sensitivity of the transducer are improved.