Effects of curing thermal residual stresses on fatigue crack propagation of aluminum plates repaired by FML patches

The aim of the present paper is to evaluate the effect of residual stresses, due to cold-drawing process, on the fatigue crack propagation in a pearlitic steel wire with a V-shaped circumferential notch. In order to analyse the effect of the notch severity on the residual stress distribution, three different values of the notch root radius are examined. The residual stress distributions in the reduced cross-section of such wires are numerically evaluated through FE analyses which simulate the material removing operation in the notched region. The stress-intensity factors (SIFs) related to tension loading and residual stresses are computed. Then, the crack propagation under cyclic tension combined with the residual stresses is analysed by taking into account the above SIF values and the actual stress ratio, which is different from that due to cyclic tension only.

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The effect of residual stresses on fatigue crack propagation in welded stiffened panels

Engineering Failure Analysis ◽

10.1016/j.engfailanal.2017.09.001 ◽

2018 ◽

Vol 84 ◽

pp. 346-357 ◽

Cited By ~ 32

Author(s):

Željko Božić ◽

Siegfried Schmauder ◽

Hinko Wolf

Keyword(s):

Fatigue Crack ◽

Residual Stresses ◽

Crack Propagation ◽

Fatigue Crack Propagation ◽

Stiffened Panels

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Measurement of Stress Distribution Near Fatigue Crack in Ultra-Fine Grained Steel by Synchrotron Radiation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.490-491.118 ◽

2005 ◽

Vol 490-491 ◽

pp. 118-123 ◽

Cited By ~ 1

Author(s):

Yoshiaki Akiniwa ◽

Keisuke Tanaka ◽

Hidehiko Kimura

Keyword(s):

Fatigue Crack ◽

Synchrotron Radiation ◽

Stress Distribution ◽

Residual Stresses ◽

Crack Propagation ◽

Fatigue Crack Propagation ◽

Crack Closure ◽

Experimental Result ◽

Ultrafine Grained ◽

Ultrafine Grained Steel

Single-edge-notched specimens of ultrafine-grained steel were fatigued. The mean grain size of the steel is about 2 micrometers. Propagation behavior of fatigue cracks was observed with the crack closure. The resistance of the crack propagation of ultrafine-grained steel was larger than that of conventional steels. The crack closure acted as an important role for the larger resistance of fatigue crack propagation. After fatigue tests, stress distribution near the fatigue crack was measured by monochromatic X-rays from synchrotron radiation. The irradiated area was 100 µm x 100 µm. Residual and loading stress distributions ahead of the crack tip and on the crack wake was measured at the maximum stress intensity factor and zero applied load. The stress was determined by sin2ψ method. The measured stress was compared with the value calculated by FEM and the fatigue crack propagation model. The stress distribution at the maximum load and residual stresses agreed very well with the calculated results. The crack opening stress calculated by the residual stresses agreed with the experimental result.

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