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Evaluation of fatigue limit and harmless crack size of needle peened offshore structure steel F690
In this study, a 0.4-1.6 mm deep semicircular crack was machined in DNV F690 offshore structural steel with an aspect ratio ( As ) of 1.0. After needle peening ( NP ), four-point bending fatigue tests were conducted. The fatigue limit estimated using the equation proposed by Ando et al. decreased wi...
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Published in: | Journal of mechanical science and technology 2021, 35(9), , pp.3855-3862 |
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Main Authors: | , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | In this study, a 0.4-1.6 mm deep semicircular crack was machined in DNV F690 offshore structural steel with an aspect ratio (
As
) of 1.0. After needle peening (
NP
), four-point bending fatigue tests were conducted. The fatigue limit estimated using the equation proposed by Ando et al. decreased with increasing crack size, but agreed with that obtained in the four-point bending fatigue test. The compressive residual stress increased the fatigue limit of the
NP
smooth and crack specimens. The fatigue limit of the
NP
crack specimen with a crack depth
a
= 0.8 mm was over 95 % of that of the smooth specimen. Semicircular cracks with crack depths up to
a
= 0.8 mm could be rendered harmless by
NP
, however, this was not the case for the
NP
crack specimen having
a
= 1.2 mm. It was estimated that the harmless crack depth of the
NP
crack specimen was
a
= 1.14 mm. |
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ISSN: | 1738-494X 1976-3824 |
DOI: | 10.1007/s12206-021-2109-4 |