Validation of modern predictive SEA for interior noise

Abstract

Statistical Energy Analysis (SEA) has traditionally been effective at predicting the transmission of acoustic power between structure and fluid and acoustic transmission between two fluids through a plate. Until recently, SEA has been less effective at predicting the vibrational power transmission directly between structural components. Modern predictive SEA, incorporating multi-wave beam and shell subsystems and more sophisticated models of the dynamics of structural joints, is better equipped to predict the direct vibration transmission problem. We compare predictions using the modern predictive SEA code AutoSEA with measurements of noise and vibration response on a carefully constructed laboratory test structure that incorporates some of the complexities seen in real aerospace structural-acoustic design applications. The test structure consists of 26 plates bounding five interior acoustic cavities, and connected together by “L” and “T” section beam-like elements. A series of comparisons between predictive SEA and test include both structural vibration and interior sound-pressure-level response to structural excitation. These calculations and comparisons reveal uncertainties and biases in the predictions that are significant but small enough to allow the method to be used with confidence.