Predicting response of a honeycomb sandwich panel to diffuse acoustic field vs turbulent boundary layer excitation using coupled finite element-boundary element approach.

Abstract

Composite materials are being extensively used in primary and secondary aerospace structures due to high specific strength and stiffness as well as low weight. In this study finite element (FE) and boundary element (BE) are used to study acoustical performance of honeycomb type structures subjected to common excitation sources in flight. Coupled FE-BE is applied to predict transmission loss (TL) of honeycomb type structure, excited by diffuse acoustic field and turbulent boundary layer. Structural FE model correlation is performed using experimental modal analysis. Transmission loss of honeycomb panel was measured at the GAUS TL Lab using diffuse acoustic field. TL results are used to validate coupled FE-BE vibro-acoustic model of a curved honeycomb panel. Correlated model is used to predict response of structure to TBL source. Effect of noise control treatments in reducing radiated noise from honeycomb panel excited by TBL and diffuse field are studied.