压电陶瓷堆位置对郎之万换能器内部损耗的影响

Influence of piezoceramic stack location on internal losses of Langevin transducer

压电陶瓷堆位置是郎之万换能器优化设计的一个重要对象,人们对其研究较多但结论并不一致。文章主要考虑压电陶瓷的机械损耗及介电损耗,分析了恒振幅输出时这两种损耗与压电陶瓷堆位置的关系,并通过引入负载系数探讨了不同负载情况下压电陶瓷堆位置对郎之万换能器内部损耗的影响。分析结果表明,对于不同的负载,压电陶瓷堆均对应一个最佳位置,此时换能器的内部损耗最小,且随着负载的增大,这一最佳位置逐渐向换能器的节点位置靠近。可见,压电陶瓷堆位置的优化设计与实际负载密切相关,以往关于该问题的不同结论源于其仅针对某种特定负载分析而得。

Piezoceramic stack location is an important optimization design object of Langevin transducer, and many researches on this topic have been done but there are no consistent conclusions. In this paper, mechanical loss and die- lectric loss of piezoceramic are mainly considered, and the relation between these two kinds of losses and the pie- zoceramic stack location is analyzed under the circumstances of constant output amplitude. Moreover, by introducing the load coefficient, the influence of the piezoceramic stack location on internal losses of Langevin transducer is dis- cussed under different load conditions. The results show the piezoceramic stack corresponds to a best location for dif- ferent loads, and at this time the internal losses of Langevin transducer is the smallest. The best location is gradually close to the displacement node of the transducer as the load increases. Thus it can be seen that the optimal design of piezoceramic stack location is closely related to the actual load, and the inconsistent conclusions about the problem by far stem from these analyses only to specific loads.