Structural acoustic modeling of aircraft fuselage structures

Abstract

Recent studies at NASA Langley Research Center have examined the development and validation of finite element and boundary element modeling techniques for the prediction of structural acoustic response of aircraft fuselage structures. The goal of this work is to provide increased confidence in the modeling techniques so that interior noise criteria can be incorporated early in the design process. These efforts have focused on the development and validation of high-fidelity physics-based numerical models for structural acoustic predictions into the kilohertz region. Finite element models were developed based on the geometric and material properties of the aircraft fuselage structures. Experimental modal analysis and point force frequency response functions were used to validate and refine the finite element models. Once validated, the finite element predictions of the velocity response were used as boundary condition input for boundary element predictions of the radiated sound power. Experiments in the Structural Acoustic Loads and transmission (SALT) Facility at NASA Langley were used to validate the acoustic predictions. Numerical and experimental results will be presented for conventional aluminum rib and stringer-stiffened aircraft structures, a honey comb composite sidewall panel, and damped acrylic windows. Numerical predictions were in good agreement with the experimental data.