Analysis of vibro-acoustic response of un-baffled laminated composite conical shell panel with varying thickness

Abstract

This article presents the vibro-acoustic modeling and analysis of un-baffled laminated composite conical shell panels with varying thickness subjected to harmonic point load. The variation of thickness is considered to be unidirectional. A simulation model for the vibrating panel is developed using the commercial finite element package (ABAQUS). The natural frequencies are computed and compared with available published values for validation purpose. Then, the modal values are exported to LMS Virtual.Lab environment where an indirect boundary element approach has been adopted to extract the coupled vibro-acoustic responses. The sound power radiated by the vibrating structure computed using the present scheme is compared with the results available in the published literature. A comprehensive study has been performed to highlight the effect of thickness variation, excitation location, lamination scheme and support conditions on the acoustic radiation responses of the laminated conical shell panel. The variation of thickness is observed to greatly influence the mode shapes of the panel thereby influencing the sound radiation characteristics. The stiffness of the panels is affected by the lamination scheme, which in addition to stiffness variation due to varying thickness alters the radiation characteristics of the panels significantly.