Finite element analysis of double resonance bender disk low frequency transducer

Abstract

A bender disk transducer can generate low-frequency sound in a small size and light weight. But traditional bender disk transducer only works at single frequency by using first order bending mode and emits moderate levels of power. In this work, a double resonance bander disk low frequency transducer is investigated by using finite element model. The double resonance bender disk transducer consists of two segmented 3-3 mode piezoelectric ceramic disk on the both side of hollow metal disc, which could generate larger displacement in order to increase power radiation. A simple elastic mass system placed inside the hollow metal disc is introduced in the system to produce other lower resonance modes. Through the FEM calculations, it is found that the transmitting voltage response (TVR) of bender disk transducer could enhance 4dB in the first order bending mode resonance frequency, which is compared with traditional bender disk transducer with the same size. The TVR of lower resonance mode which is produced by additional central simple support elastic mass system in segmented bender disk transducer is more than 130dB. Through the optimization of finite element simulation, a double resonance bender disk transducer is designed, and its resonance frequency is 600Hz and 1kHz, respectively. The value of TVR is 130dB and 134dB corresponding to two resonance frequency. The double resonance bender disk transducer is compact dimension, low weight and it is a high performance low frequency transducer.