NOISE PATH DIAGNOSTICS IN DISPERSIVE STRUCTURAL SYSTEMS USING CROSS-CORRELATION ANALYSIS

A common problem in noise control is the identification of the dominant paths from a known noise-source in a structural system to a receiver in or near the system. This diagnosis is complicated in large structural systems (such as aeroplanes, ships, and piping systems) by the existence of multiple paths between each source and the receiver. Some of these are paths of non-dispersive noise propagation, and cross-correlation analysis has been used to identify them. Many of them are, however, dispersive propagation paths, and although cross-correlation analysis has been used for their identification, the analysis has been limited to relatively low-frequency noise, short paths, and a single dispersive model. The present Author extends cross-correlation analysis to broad-band noise propagating over arbitrarily long paths, explains and discusses the procedure, and illustrates this method of diagnosis with an example in which it is used to determine that paths which noise from a ship's propellers reaches sound receivers near the bows. In this example, without the cross-correlation measurement it would have been assumed that the noise path was through the water (whereas only about 1% of the noise reached the ship's bows in this way). It is recommended that a broad-band dispersion check should always be made when trying to separate structural and fluid noise-paths.

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  • Corporate Authors:

    Institute of Noise Control Engineering

    Iowa State University, 210 Marston Hall
    Ames, IA  USA  50011-2153

    Ray Herrick Laboratories

    Purdue University
    West Lafayette, Indiana,   USA  47907
  • Authors:
    • Barger, J E
  • Publication Date: 1976-5

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Filing Info

  • Accession Number: 00156279
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Jun 22 1977 12:00AM