scholarly journals Failure Behavior of T-joint Pipe with Outer Local Wall Thinning under Internal Pressure

2014 ◽  
Vol 18 (5) ◽  
pp. 80-87
Author(s):  
Soo-Young Kim ◽  
Ki-Woo Nam
Keyword(s):  
Internal Pressure ◽  
Failure Behavior ◽  
Wall Thinning ◽  
Local Wall Thinning

An Experimental Study on the Evaluation of Failure Behavior of Pipe With Local Wall Thinning

2002 ◽  
Author(s):  
Jin Weon Kim ◽  
Chi Yong Park
Keyword(s):  
Internal Pressure ◽  
Failure Mode ◽  
Carrying Capacity ◽  
Axial Length ◽  
Failure Behavior ◽  
Load Carrying Capacity ◽  
Wall Thinning ◽  
Load Carrying ◽  
Deformation Ability ◽  
Local Wall Thinning

The pipe failure tests were performed using 102mm-Sch.80 carbon steel pipe with various simulated local wall thinning defects, in the present study, to investigate the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The failure mode, load carrying capacity, and deformation ability were analyzed from the results of experiments conducted under loading conditions of 4-point bending and internal pressure. A failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Also, the results indicated that the load carrying capacity and deformation ability were depended on stress state in the thinning region and dimensions of thinning defect. With increase in axial length of thinning area, for applying tensile stress to the thinning region, the dependence of load carrying capacity was determined by circumferential thinning angle, and the deformation ability was proportionally increased regardless of the circumferential angle. For applying compressive stress to thinning region, however, the load carrying capacity was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area.

Effect of Circumferential Location of Local Wall Thinning Defect on the Collapse Moment of Elbow

2006 ◽  
Author(s):  
Jin Weon Kim ◽  
Yeon Soo Na ◽  
Chi Yong Park
Keyword(s):  
Carbon Steel ◽  
Internal Pressure ◽  
Nuclear Power ◽  
Three Dimensional ◽  
Piping System ◽  
Main Concern ◽  
Wall Thinning ◽  
Bending Load ◽  
Local Wall Thinning ◽  
Steel Piping

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.

Failure Behavior of Carbon Steel Pipe Having Local Wall Thinning Near Tee Joint

2006 ◽  
Author(s):  
Kotoji Ando ◽  
Koji Takahashi ◽  
Masakazu Hisatsune ◽  
Kunio Hasegawa
Keyword(s):  
Finite Element Method ◽  
Three Dimensional ◽  
Metal Loss ◽  
Failure Behavior ◽  
Fracture Type ◽  
Bending Tests ◽  
Four Point Bending ◽  
Wall Thinning ◽  
Erosion Corrosion ◽  
Local Wall Thinning

Monotonic four-point bending tests were conducted using tee pipe specimens having local wall thinning. The effects of local wall thinning on the failure behaviors of tee pipes were investigated. Local wall thinning was machined on the inside of pipes in order to simulate erosion/corrosion metal loss. The configurations of the eroded area were l = 100 mm in eroded axial length, d/t = 0.5 and 0.8 in eroded ratio, and 2θ = 90° and 180° in eroded angle. The area undergoing local wall thinning was subjected to tensile stress. It was found that fracture type could be classified into ovalization or crack initiation, depending on eroded ratio. Three-dimensional elasto-plastic analyses were also carried out using finite element method to discuss the effects of position and geometries of wall thinning in both tee pipes and straight pipes.

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

2007 ◽  
Vol 237 (4) ◽  
pp. 335-341 ◽  
Author(s):  
Koji Takahashi ◽  
Kotoji Ando ◽  
Masakazu Hisatsune ◽  
Kunio Hasegawa
Keyword(s):  
Carbon Steel ◽  
Steel Pipe ◽  
Failure Behavior ◽  
Wall Thinning ◽  
Local Wall Thinning

1108 Effect of External Local Wall Thinning on The Failure Behavior of Pressure Vessel

2006 ◽  
Vol 2006.81 (0) ◽  
pp. _11-8_
Author(s):  
Ja-Moon YOON ◽  
Kotoji ANDO ◽  
Koji TAKAHASHI ◽  
Hideo ANDO ◽  
Ki-Woo NAM
Keyword(s):  
Pressure Vessel ◽  
Failure Behavior ◽  
Wall Thinning ◽  
Local Wall Thinning

3428 Finite element analysis of failure behavior of elbow pipe with local wall thinning

2006 ◽  
Vol 2006.1 (0) ◽  
pp. 567-568
Author(s):  
Tomohiro UENO ◽  
Koji TAKAHASHI ◽  
Kotoji ANDO ◽  
Akitaka HIDAKA ◽  
Masakazu HISATSUNE ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Failure Behavior ◽  
Element Analysis ◽  
Wall Thinning ◽  
Local Wall Thinning
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