Correlation of structural-acoustic testing and finite element analysis of aircraft cabin noise control designs

摘要

When developing airplane cabin noise control, it is a challenge to represent the in-flight environment within a laboratory setting. But the performance of noise reducing damping systems for aircraft primary structure is sensitive to both temperature and in-flight static pressure loading. The complexity of these systems merits a joint test and analysis approach, to gain a better understanding of the combined environment physics that affect viscoelastic damping treatment design. The uniqueness of the current work is in pushing the experimental capability to curved, rib-stiffened test articles that exhibit the desired structural-dynamic behavior. The combined thermal and pressure environmental test requires advancements in test methods, control systems, and hardware. Advancements in data analysis, including the processing of damping loss factors over arrays of frequency, pressure, and temperature, are also required. The experimental results are augmented with numerical analysis to translate to airplane-level performance. Finite Element Methods (FEM) are used for validation of the stress, non-linear displacements, modal dynamics, and system loss factors of the test articles. The Finite Element (FE) models are used to account for the finite test panel and the influence of boundary conditions. The objective is to understand the complex behavior of noise control damping systems in a representative flight environment and translate this understanding into specifications and compliance test methods for the commercialization of lighter, more effective noise control treatments.