Advances in Flextensional Transducer Design

A continued need for wide-bandwidth, high-power transducers which are acoustically small has prompted the development of more advanced flextensional transducers. The direction of the newer designs is toward lower frequencies, lighter weight, and higher power densities. These gains have been made without sacrificing the low Q and physical ruggedness that characterize the flextensional approach. Some of the techniques discussed in the paper are the use of fibre-reinforced composite shell materials which can result in a lower frequency for a given size and lower Q and lighter weight for a given depth and frequency, and the effect of static and dynamic stresses on transducer depth, power, and endurance. The ideas presented are illustrated with test results on an actual unit and directions for future development in this area are outlined.