Accession Number : AD0743312

Title :   Nondestructive Evaluation of Metal Fatigue.

Descriptive Note : Scientific rept.,

Corporate Author : SOUTHWEST RESEARCH INST SAN ANTONIO TEX DEPT OF INSTRUMENTATION RESEARCH

Personal Author(s) : Kusenberger,F. N. ; Lankford,J. , Jr. ; Francis,P. H. ; Barton,J. R.

Report Date : APR 1972

Pagination or Media Count : 80

Abstract : The important role of nondestructive evaluation (NDE) methods in complementing the tools of fracture mechanics for preventing catastrophic fatigue failures in engineering structures is discussed. Magnetic perturbation signatures from surface and subsurface fatigue cracks in AISI 4340 steel rod-type axially loaded specimens are illustrated, compared, and considered in terms of the plastic zone and residual stresses in the vicinity of the fatigue cracks. Also, magnetic records from drilled holes and fatigue cracks in 4340 and maraging steels are presented which show significant differences in response from the two materials. Preliminary acoustic emission investigations on rod-type specimens containing surface fatigue cracks are reviewed and the results compared with those from single edge-notched flat specimens. (Author)

Descriptors :   (*STEEL, FATIGUE(MECHANICS)), (*NONDESTRUCTIVE TESTING, FATIGUE(MECHANICS)), MAGNETIC PROPERTIES, ACOUSTIC PROPERTIES, CRACKS, METALS

Subject Categories : Metallurgy and Metallography
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE