Abstract:
Energy finite-element models of structural acoustic systems require input of transmission and reflection coefficients at the joints between systems as well as loss factors and group speeds of the media. Methods have been reported previously for measurement of these properties [R. J. Unglenieks and R. J. Bernhard, J. Acoust. Soc. Am. 97, 3331(A) (1995)]. In this paper, measured parameters for the round robin T-beam structure and a bolted joint will be shown. The results for the T-beam compare well with theoretical values for thick beam behavior. The bolted beam study was used to examine the variation that might be encountered in assembled systems. The variation was found to be significant. Energy finite-element predictions of the response compared favorably to measured results.