Hygrothermal effects on structure-borne noise transmission of stiffened laminated composite plates

Abstract

This paper examines the effect of elevated temperatures, absorbed moisture, and random external excitation on the dynamic response and structure-borne noise transmission of discretely stiffened flat plates from laminated composite material. An analytical approach using modified transfer matrices for composite stiffened flat panels, including the hygrothermal effects, is developed to obtain the required dynamic response solution. Ingestion of moisture and changes of temperature levels were taken to vary linearly with the swelling, which results in effective force resultants. The dynamic response is calculated from the total hygrothermal and mechanical loading environment. The theoretical solutions of the governing acoustic-structural equations for the transmitted noise are obtained using modal decomposition. The acoustic enclosure is taken to be rectangular in shape, a portion of its boundaries is elastic (composite material), while the remaining surface is acoustically rigid. Numerical results are presented for acousto-structural applications revealing the hygrothermal effect on composite materials.