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Xiaoping Huang - One of the best experts on this subject based on the ideXlab platform.

  • A unique Crack Growth Rate curve method for fatigue life prediction of steel structures
    Ships and Offshore Structures, 2009
    Co-Authors: Xiaoping Huang, Torgeir Moan
    Abstract:

    In this paper, a unique Crack Growth Rate curve method, which is based on the equivalent stress intensity factor range (ESIFR) as the driving force, has been proposed and examined with Crack Growth Rate data of base metals and as welded joints of some structural steels under constant amplitude external loading. By expressing the Crack Growth Rate data with ESIFR instead of stress intensity factor range (SIFR) make it possible to establish a concise model for Crack Growth data under different R-ratios to the curve corresponding to R=0 both for base metals and welded joints. The most commonly tested Crack Growth Rate constants under R=0 ∼0.1 are sufficient in fatigue Crack Growth life prediction of components subjected to tensile-tensile, tensile-compressive loading. Only two equations, one for Mean curve, and the other for Mean + 2SD curve replace the recommended Crack Growth Rate curves in BS7910 for most structural steels. The phenomena that Crack Growth Rates of as-welded joints under different applied ...

  • improved modeling of the effect of r ratio on Crack Growth Rate
    International Journal of Fatigue, 2007
    Co-Authors: Xiaoping Huang, Torgeir Moan
    Abstract:

    Abstract Most engineering structures with Crack-like defects experience varying Crack-tip loading during their service. This variation may result from combinations of varying applied loads and displacements and/or varying body force including residual stress. It is known that Crack Growth Rates differ according to the R -ratios when expressed via a single parameter, stress intensity factor range, Δ K . Many methods have been proposed to incorpoRate the effect of the R -ratio, including effective stress intensity factor range models based on Crack closure and the two-parameter driving force model etc. However there are few clear statements about the choice of material constants for the calculation of Crack Growth lives under varying amplitude loading. This is a significant omission. In this paper, a simple Crack Growth Rate equation has been proposed, which can condense the Crack Growth data under different R -ratios to the curve corresponding to R  = 0. Fatigue Crack Growth Rate data for several materials taken from the literature, were analyzed using a new formulation. These data then cluster around the R  = 0 Crack Growth Rate curve. The result implies that Crack Growth Rates for fatigue life calculation under different R -ratios may be obtained directly from the constants corresponding to R  = 0. Thus the most commonly tested Crack Growth Rate constants corresponding to R  = 0–0.1 are sufficient for fatigue Crack Growth calculation under different loading conditions.

  • Fatigue Crack Growth Rate Recommended in BS7910 and an Unique Crack Growth Rate Curve Under Different Load Ratios
    Volume 1: Codes and Standards, 2007
    Co-Authors: Xiaoping Huang
    Abstract:

    It is still difficult to select the proper constants of Crack Growth Rate corresponding to the loading condition for R-ratio has significant effect on Crack Growth Rate. An unique Crack Growth Rate equation, taking equivalent stress intensity factor range (ESIFR) as the driving force, has been examined for steels and as welded joints. An empirical equation of β for structural steels has been presented. The Crack Growth Rate data expressed by ESIFR instead of SIFR (stress intensity factor range) condensing the Crack Growth data under different R-ratios to the curve corresponding to R = 0. The most commonly tested Crack Growth Rate constants under R = 0∼0.1 are sufficient in fatigue Crack Growth calculation under different loading condition. Furthermore, the Crack Growth Rate constants for fatigue life calculation under different R-ratios can be obtained directly from the Crack Growth Rate data tested under any given constant R-ratio test conditions according to the relationship between ESIFR and SIFR. This deduction can greatly reduced the requirement of quantity and cost of fatigue tests for determining the constants of Crack Growth Rate. The gape between the curves corresponding to R

Torgeir Moan - One of the best experts on this subject based on the ideXlab platform.

  • A unique Crack Growth Rate curve method for fatigue life prediction of steel structures
    Ships and Offshore Structures, 2009
    Co-Authors: Xiaoping Huang, Torgeir Moan
    Abstract:

    In this paper, a unique Crack Growth Rate curve method, which is based on the equivalent stress intensity factor range (ESIFR) as the driving force, has been proposed and examined with Crack Growth Rate data of base metals and as welded joints of some structural steels under constant amplitude external loading. By expressing the Crack Growth Rate data with ESIFR instead of stress intensity factor range (SIFR) make it possible to establish a concise model for Crack Growth data under different R-ratios to the curve corresponding to R=0 both for base metals and welded joints. The most commonly tested Crack Growth Rate constants under R=0 ∼0.1 are sufficient in fatigue Crack Growth life prediction of components subjected to tensile-tensile, tensile-compressive loading. Only two equations, one for Mean curve, and the other for Mean + 2SD curve replace the recommended Crack Growth Rate curves in BS7910 for most structural steels. The phenomena that Crack Growth Rates of as-welded joints under different applied ...

  • improved modeling of the effect of r ratio on Crack Growth Rate
    International Journal of Fatigue, 2007
    Co-Authors: Xiaoping Huang, Torgeir Moan
    Abstract:

    Abstract Most engineering structures with Crack-like defects experience varying Crack-tip loading during their service. This variation may result from combinations of varying applied loads and displacements and/or varying body force including residual stress. It is known that Crack Growth Rates differ according to the R -ratios when expressed via a single parameter, stress intensity factor range, Δ K . Many methods have been proposed to incorpoRate the effect of the R -ratio, including effective stress intensity factor range models based on Crack closure and the two-parameter driving force model etc. However there are few clear statements about the choice of material constants for the calculation of Crack Growth lives under varying amplitude loading. This is a significant omission. In this paper, a simple Crack Growth Rate equation has been proposed, which can condense the Crack Growth data under different R -ratios to the curve corresponding to R  = 0. Fatigue Crack Growth Rate data for several materials taken from the literature, were analyzed using a new formulation. These data then cluster around the R  = 0 Crack Growth Rate curve. The result implies that Crack Growth Rates for fatigue life calculation under different R -ratios may be obtained directly from the constants corresponding to R  = 0. Thus the most commonly tested Crack Growth Rate constants corresponding to R  = 0–0.1 are sufficient for fatigue Crack Growth calculation under different loading conditions.

R.n. Ibrahim - One of the best experts on this subject based on the ideXlab platform.

R. Rihan - One of the best experts on this subject based on the ideXlab platform.

Xuelian Xu - One of the best experts on this subject based on the ideXlab platform.

  • scc Crack Growth Rate of cold worked 316l stainless steel in pwr environment
    Journal of Nuclear Materials, 2015
    Co-Authors: Donghai Du, Kai Chen, Lun Yu, Hui Lu, Lefu Zhang, Xuelian Xu
    Abstract:

    Abstract Many component failures in nuclear power plants were found to be caused by stress corrosion Cracking (SCC) of cold worked austenitic steels. Some of the pressure boundary component materials are even cold worked up to 35% plastic deformation, leaving high residual stress and inducing high Growth Rate of corrosion Crack. Controlling water chemistry is one of the best counter measure to mitigate this problem. In this work, the effects of temperature (200 up to 325 °C) and dissolved oxygen (0 up to 2000 μg/L) on SCC Crack Growth Rates of cold worked austenitic stainless steel type 316L have been tested by using direct current potential drop (DCPD) method. The results showed that temperature affected SCC Crack Growth Rates more significantly in oxygenated water than in deaeRated water. In argon deaeRated water, the Crack Growth Rate exhibited a peak at about 250 °C, which needs further verification. At 325 °C, the SCC Crack Growth Rate increased rapidly with the increase of dissolved oxygen concentration within the range from 0 up to 200 μg/L, while when dissolved oxygen was above 200 μg/L, the Crack Growth Rate followed a shallower dependence on dissolved oxygen concentration.