Determination of the mechanical limits of piezoelectric transducers using the finite element method

Abstract

The mechanical limit of ultrasonic transducers is associated with the fracture, nonlinearities, and fatigue strength of the different materials and thus is directly related to the distribution of stresses over the structure. The static case corresponds generally to the design of depth transducers and prestressed ceramic stacks. The dynamic case concerns high‐power sonar transducers, as well as macrosonics. For several transducers, the stress field has been computed with the help of a finite element modeling, using the ATILA code [J. N. Decarpigny et al., J. Acoust. Soc. Am. 78, 1499 (1985)]. This paper describes such an analysis in the case of an axisymmetrical length expander transducer and a flexural shell sonar transducer [B. Hamonic et al., J. Acoust. Soc. Am. Suppl. 1 80, S26 (1986)]. The static stresses distribution is found when a mechanical bias is applied and maximum dynamic stress zones are identified at several frequencies, using a classical fatigue criterion. Measurements with strain gauges di...