Fracture behavior of carbon steel pipe with local wall thinning subjected to bending load

Local wall-thinning due to flow-accelerated corrosion is one of the degradation mechanisms of carbon steel piping in nuclear power plant (NPP). It is a main concern in carbon steel piping systems in terms of the safety and operability of the NPP. Recently, the integrity of piping components containing local wall-thinning has become more important for maintaining the reliability of a nuclear piping system, and has been the subject of several studies. However, although wall-thinning in pipe bends and elbows has been frequently reported, its effect on the integrity of pipe bends and elbows has not yet been systematically investigated. Thus, the purpose of this study was to investigate the effect of the circumferential location of a local wall-thinning defect on the collapse behavior of an elbow. For this purpose, the present study used three-dimensional finite element analyses on a 90-degree elbow containing local wall-thinning at the crown of the bend region and evaluated the collapse moment of the wall-thinned elbow under various thinning geometries and loading conditions. The combined internal pressure and bending loads were considered as an applied load. Internal pressure of 0∼20 MPa and both closing-and opening-mode bending were applied. The results of the analyses showed that a reduction in the collapse moment of the elbow due to local wall-thinning was more significant when a defect was located at the crown than when a defect was located at the intrados and extrados. Also, the effect of the internal pressure on the collapse moment depended on the circumferential location of the thinning defect and mode of the bending load.

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Failure behavior of carbon steel pipe with local wall thinning near orifice

Nuclear Engineering and Design ◽

10.1016/j.nucengdes.2006.04.033 ◽

2007 ◽

Vol 237 (4) ◽

pp. 335-341 ◽

Cited By ~ 20

Author(s):

Koji Takahashi ◽

Kotoji Ando ◽

Masakazu Hisatsune ◽

Kunio Hasegawa

Keyword(s):

Carbon Steel ◽

Steel Pipe ◽

Failure Behavior ◽

Wall Thinning ◽

Local Wall Thinning

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An Eddy Current Method to Evaluate Local Wall Thinning of Carbon Steel Pipe

Studies in Applied Electromagnetics and Mechanics - Electromagnetic Non-Destructive Evaluation (XXIII) ◽

10.3233/saem200005 ◽

2020 ◽

Author(s):

Shanshan Sun ◽

Deqianga Zhou ◽

Noritaka Yusa ◽

Haicheng Song

Keyword(s):

Carbon Steel ◽

Correlation Analysis ◽

Eddy Current ◽

Gaussian Process Regression ◽

Current Method ◽

Steel Pipe ◽

Eddy Current Method ◽

Wall Thinning ◽

Simulation And Experiment ◽

Local Wall Thinning

This paper proposes to evaluate the local wall thinning of carbon steel pipe using an eddy current method. Firstly, the feature signals are determined by correlation analysis of the signals and the wall thinning sizes. Subsequently, the models for estimating the residual wall thickness rt is constructed using Gaussian process regression (GPR). Finally, the applicability of the models to the evaluation of local wall thinning is verified by simulation and experiment.

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A Study on Experimental Evaluation for Fracture Behavior of Carbon Steel Pipes for High Pressure Service with Local Wall Thinning

The Mechanical Behavior of Materials X - Key Engineering Materials ◽

10.4028/0-87849-440-5.1349 ◽

2007 ◽

pp. 1349-1352

Author(s):

Seok Hwan Ahn ◽

Kum Cheol Seok ◽

Ki Woo Nam

Keyword(s):

High Pressure ◽

Carbon Steel ◽

Experimental Evaluation ◽

Fracture Behavior ◽

Steel Pipes ◽

Wall Thinning ◽

Local Wall Thinning

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Fracture strength and behavior of carbon steel pipes with local wall thinning subjected to cyclic bending load

Nuclear Engineering and Design ◽

10.1016/s0029-5493(02)00021-3 ◽

2002 ◽

Vol 214 (1-2) ◽

pp. 127-136 ◽

Cited By ~ 23

Author(s):

Katsumasa Miyazaki ◽

Akira Nebu ◽

Masayuki Ishiwata ◽

Kunio Hasegawa

Keyword(s):

Carbon Steel ◽

Fracture Strength ◽

Cyclic Bending ◽

Steel Pipes ◽

Wall Thinning ◽

Bending Load ◽

And Behavior ◽

Local Wall Thinning

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424 Failure behavior of carbon steel pipe having local wall thinning near T-joint

Proceedings of the 1992 Annual Meeting of JSME/MMD ◽

10.1299/jsmezairiki.2005.0_303 ◽

2005 ◽

Vol 2005 (0) ◽

pp. 303-304

Author(s):

Koji TAKAHASHI ◽

Ken INOUE ◽

Kotoji ANDO ◽

Masakazu HISATSUNE ◽

Kunio HASEGAWA

Keyword(s):

Carbon Steel ◽

Steel Pipe ◽

Failure Behavior ◽

Wall Thinning ◽

Local Wall Thinning

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Evaluation of Wall-Thinning in Pipes Using Laser-Generated Guided Waves

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.326-328.705 ◽

2006 ◽

Vol 326-328 ◽

pp. 705-708

Author(s):

Jong Ho Park ◽

Joon Hyun Lee ◽

Min Rae Lee

Keyword(s):

Carbon Steel ◽

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Guided Waves ◽

Single Mode ◽

Steel Pipe ◽

Wall Thinning ◽

Structural Fracture ◽

Local Wall Thinning

Local wall thinning is one of the major causes for the structural fracture of pipes of nuclear power plants. Therefore, assessment of local wall thinning due to corrosion is an important issue in nondestructive evaluation for the integrity of nuclear power plants. In this study, lasergenerated guided waves were used for pipe inspection, where a laser beam illuminated through linear slit array was used as the transmitter and the air-coupled transducer was used as the receiver. Slits was used in order to enhance the mode-selectivity of guided waves, since the space of slits is equal to the wavelength of the generated wave. The air-coupled transducer detected the selected single mode by turning its detection angle that was calculated from the relations between the wave propagation velocity in air and the phase velocity in dispersion curves. Experimental results for a 4- mm thick carbon steel pipe showed that the detection of the specific mode was useful in the distinction of the wall-thinning thickness in the carbon steel pipe.

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