Accession Number : AD0774490

Title :   Acoustic Emission as an Index of Submarine Hull Integrity.

Descriptive Note : Memorandum rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Chaskelis,H. H.

Report Date : JAN 1974

Pagination or Media Count : 22

Abstract : Two large flat steel plates (one 6X20 ft., 2 in. thick of HY-80; the other 8X18 ft., 2-1/2 in. thick of HY-140) are used as test specimens to realistically evaluate with respect to size the wave propagation characteristics of acoustic emissions. Wide band transducers, amplifiers and video-tape recorders are used to capture and store the acoustic signals generated by various means. The video-tapes are then analyzed by replay to an oscilloscope and a spectrum analyzer. Preliminary data reduction indicates that sound propagates faithfully over appreciable distances. However a distinction is not apparent, in the frequency domain, between emissions from crack extension and signals from other sources not related to this phenomenon. (Author)

Descriptors :   *Submarine hulls, *Nondestructive testing, *Acoustic emissions, Acoustic waves, Metal plates, Steel, Cracks, Sound transmission

Subject Categories : Fabrication Metallurgy
      Marine Engineering
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE