The acoustic radiation analysis of SFGP conical shell

Abstract

The shell of revolution made of sandwich functionally graded material (SFGM) has broad applications in engineering. Pores are inevitable in processing SFGM, making it complex for the vibro-acoustic characteristics of the structure. To analyze the acoustic radiation mechanism of sandwich functional gradient porous materials (SFGP) shells deeply, a theoretical model for vibro-acoustic coupling of SFGP shells based on a semi-analytical approach is proposed. The spectral boundary element approach is used to simulate the sound field while the energy method is utilized for representing the structural field. The substructure scheme is introduced, resulting in a uniform division of both the structural field and the sound field into several segments. Similarly, both the displacement and sound pressure are depicted in an identical manner, with the meridional direction expanded using the Legendre series and the circumferential direction expanded using the Fourier series. By introducing the virtual work done by the sound pressure, the structural and sound fields are coupled to form the vibro-acoustic coupling equation, which is solved using the strong coupling approach. The present method exhibits outstanding convergence and precision, showcasing a strong agreement in vibro-acoustic response results when compared to prior research. Since the conical shell is one of the most widely applicable shells of revolution, this paper takes the conical shell as the research object to study. Following the proposed methodology, we delve into the examination of the roles played by various circumferential wave number modes in influencing the vibro-acoustic response of SFGP conical shells. Building upon this groundwork, an investigation is conducted into the influence of factors such as material gradient index, porosity, and pore distribution on the vibro-acoustic characteristics of SFGP conical shells.