STUDIES ON THE EVALUATION OF CORROSION FATIGUE CRACK INITIATION LIFE ON NOTCHED STEEL PLATE

In the ballast tank of oil tanker and offshore structures, corrosion damage caused by the sea water and fatigue damage occurring by wave-induced forces are induced simultaneously. So the fatigue cracks are often initiated in the members of such structures, even if stress lower than the fatigue limit in the air acts on those in the sea water. In this study, fatigue crack initiation life N sub c of a notched steel plate subjected to pulsating tensile load in the air or sea water was analyzed theoretically by applying Neuber's rule with stress-strain function D proposed by Topper et al as a parameter of damage. Experiments were carried out with notched plate specimens, of which the elastic stress concentration factor K sub t were varied from 1.0 to 6.0, under pulsating tensile loading fatigue test in order to verify the theoretical analysis. The completely reversed strain controlled fatigue test was conducted with a smooth round-bar specimen in consideration of a reversed stress state induced at the notch root under pulsating tensile loading. Results of pulsating tensile loading fatigue test of the notched specimen were in a good agreement with theoretical values evaluated with stress-strain function from completely reversed strain-controlled fatigue test results. The corrosion effect factor K sub c of notched specimen was expressed as an exponential function of corrosion time T sub c corresponding to N sub c irrespective of K sub t value, and the K sub c of smooth specimen was less than that of notched specimen because of the difference of corrosion action.

  • Supplemental Notes:
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  • Corporate Authors:

    Society of Naval Architects of Japan

    15-16, Toranomon, 1-chome, Minato-ku
    Tokyo,   Japan 
  • Authors:
    • NAGAI, K
    • Mori, M
    • Yajima, H
    • YAMAMOTO, Y
    • Fujimoto, Yuusuke
  • Publication Date: 1978

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Filing Info

  • Accession Number: 00194328
  • Record Type: Publication
  • Source Agency: Society of Naval Architects of Japan
  • Files: TRIS
  • Created Date: Jun 13 1979 12:00AM