Structural-Acoustic Analysis inside Rectangular CompositeCavity with one flexible panel

Abstract

In this vibro-acoustic problem, an acoustic domain is confined within a laminated composite rectangular
rigid enclosure with one flexible wall at the end, subjected to harmonic excitement. From the finite element free vibration
analysis a mobility relation is derived to relate acoustic pressure and structural velocity normal to the containing
structure. Boundary element method is used with 8 noded quadratic isoparametric elements to analyze the acoustic
cavity from pressure-velocity formulation. Velocity is specified for the rigid part of the boundary. The pressure boundary
values are solved from the boundary element equations coupled with the mobility relations, while the velocity at flexible
boundary is computed from mobility relationship. Sound pressure levels at boundary as well as inside the domain at
various interior points reveal the effects of the length of the laminated composite cavity with the variation in wall
thickness, increase in damping and increase in number of layers