Abstract: A brass-piezoelectric ceramic composite actuator with a large displacement and a good load-bearing capabil -ity was manufactured by agglutinating and solidifying the cavity brass and the ceramic with conductive glue．The piezoelectric coefficient of d 33 more than2000pC／N was obtained in experiments．The piezoelectric and displacement properties of the actuator were systematically analyzed and the relationship between the geometric parameters and the actuating properties of the actuator was discussed．The results show that the cavity positioned between the metal end caps and the ceramic can convert and amplify the radial displacement of piezoelectric ceramics into a larger axial dis-placement of the whole structure‚and that with the decrease of brass thickness‚the resonant frequency of the actuator decreases obviously‚while the axial displacement increases obviously．

Key words: actuator, piezoelectric ceramic, geometric parameter, actuating property