Design of a Circular Clamped Plate Excited by a Voice Coil and Piezoelectric Patches Used as a Loudspeaker

Abstract

In this article, a dynamical model of the vibrations and acoustic radiation of a circular clamped plate excited by a voice coil and two annular piezoelectric patches is derived. This model is used to perform an optimization of the geometries with the objective to minimize the vibration of the plate along its second and third modes, so that the plate's radiation is equilibrated between its first and fourth eigenfrequencies. Experiments are then performed and show a good agreement with the model. Radiation of the designed system presents improvements when compared to a system when only a voice coil is used.

Tailoring Plate Thickness of a Helmholtz Resonator for Improved Sound Attenuation

“…Investigators have previously applied analytical and optimization techniques to the development of acoustic devices. In an effort to develop flat loudspeakers, Doaré et al [5] derived a dynamic model of a circular clamped plate in the presence of excitations from a voice coil and piezoelectric patches. An optimization study was carried out to design the geometry of the voice coil and patches to maximize the amplitude of the first mode while minimizing the amplitude at other modes.…”

“…In this equation, the first term in the bracket ∂ H ∂ x is the explicit derivative of H (resonator assembly frequency response) to a design variable in (5) and their dependencies in (6). For thickness design variables this term is zero.…”

Tailoring Plate Thickness of a Helmholtz Resonator for Improved Sound Attenuation

“…In an effort to develop flat loudspeakers, Doaré et al [5] derived a dynamic model of a circular clamped plate in the presence of excitations from a voice coil and piezoelectric patches. An optimization study was carried out to design the geometry of the voice coil and patches to maximize the amplitude of the first mode while minimizing the amplitude at other modes.…”