Abstract:
A hybrid analytic-numeric formulation for the time harmonic structural acoustics problem is presented. The variational framework for the seamless inclusion of analytic solutions into the Galerkin finite element formulation for a fluid-loaded structure and results of the application of this method are given. One goal of this formulation is to increase overall efficiency by eliminating regions of the structure from the computational domain via an analytic representation of the response. In this way, the total degrees of freedom present in the problem will be reduced. This reduction in the degrees of freedom enables higher frequency, more complex problems to be solved by decreasing memory requirements and compute time. The analysis of complex structures, comprised of structural members coupled at joints, is facilitated by this approach. Using a discretization of the equations of elasticity for the joint, its response may be represented to a desired level of accuracy. The elasticity representation is coupled to the reduced plate or shell theory producing an efficient model of the complete structure. The effect of the joint and the level of modeling detail required for the desired fidelity of prediction for the vibration and acoustic response of the system are studied.