Sound transmission loss of orthotropic sandwich panels with soft core and noise control treatment

摘要

A new improved model of diffuse field acoustic transmission in symmetrical sandwichpanels with thin skins and a soft core is presented in this paper. Generally, asymmetricmotion is the only dynamic behaviour which is considered in the modeling of sandwichpanels. Bending and membrane behaviour are considered in the skins while the core isassumed to be incompressible over the thickness and experiences only shearingdeformations. This set of assumptions is suitable for structures with relatively stiff and thincores. However, the symmetric mode of motion becomes important for panels with thickand soft cores which exhibit significant compression deformations over the thickness.In this paper, both symmetric and asymmetric modes of motion are considerednumerically. Their impact on the transmission loss is addressed in the configuration of asandwich panel with attached multilayer Noise Control Treatment (NCT). Experimentaland literature results are compared with the numerical simulations using the presenttheoretical approach in order to prove the validity and effectiveness of this approach.