The acoustic analysis program area is concerned with the use of advanced data processing techniques to perform vibration analysis of mechanical structures. The application is the nondestructive testing of U.S. Army material. Basically, the procedure utilized is to tap the mechanical structure to excite characteristic vibrations. The resultant sound waves produced by these vibrations are picked up and fed to a signal processing device (digital computer) which is programmed to analyze the waveform characteristic patterns and then decide as to the material integrity of the mechanical structure. This paper outlines such a procedure and describes certain initial results. The physical foundations of the method and the requirement for preliminary analytical study of the vibration characteristics of the mechanical structure being examined as a guide to anticipated waveform patterns which are required for programming of the signal analyzer are discussed. The role played by such salient features as principal vibration modes, beat frequencies, damping ratios, phase shifts, as well as harmonics of the principal modes are described. The methods of detecting features such as spectral analysis, correlation techniques, plots of data in two or more dimensions, and expansion of data into nontrigonometric orthogonal functions appropriate to diagonostic purposes are also discussed.

  • Corporate Authors:

    American Society for Testing and Materials (ASTM)

    100 Barr Harbor Drive, P.O. Box C700
    West Conshohocken, PA  United States  19428-2957
  • Authors:
    • Hoffman, B
  • Publication Date: 1972-6

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Filing Info

  • Accession Number: 00034660
  • Record Type: Publication
  • Source Agency: Materials Research and Standards
  • Files: TRIS
  • Created Date: Sep 27 1972 12:00AM