Welding Defect Analysis in Thin-Walled Steel Tube under Bending Moment

2011 ◽  
Vol 94-96 ◽  
pp. 1711-1714
Author(s):  
Jin Feng Geng ◽  
Hong Sheng Cai ◽  
Xing Pei Liang ◽  
Hui Wang ◽  
Yu Jie Wang ◽  
...  
Keyword(s):  
Stress Intensity ◽  
Bending Moment ◽  
Steel Tube ◽  
Circular Arc ◽  
Linear Elastic ◽  
Weld Defect ◽  
Bending Load ◽  
Thin Walled ◽  
Welding Defect ◽  
Circular Arc Crack

The linear elastic problem for two welded thin-walled steel tubes containing circular arc weld defect subjected to bending load is analyzed in the present paper. The welding defect is firstly simplified as a circular arc crack and then the finite element based technique is used to calculate the corresponding energy release rate (J-integral), which is related to stress intensity factor directly. Finally, the arc length of welding defect is changed to investigate the variation of stress intensity factors.

In-Plane Bending Fracture of a Large Beam Containing a Circular-Arc Crack

2002 ◽  
Vol 18 (3) ◽  
pp. 145-151
Author(s):  
Y. C. Shiah ◽  
Jiunn Fang ◽  
Chin-Yi Wei ◽  
Y.C. Liang
Keyword(s):  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Complex Stress ◽  
Bending Moments ◽  
Intensity Factors ◽  
Boundary Equation ◽  
Circular Arc ◽  
Stress Functions ◽  
Arc Crack ◽  
Circular Arc Crack

AbstractIn this paper, the crack problem of a large beam-like strip weakened by a circular arc crack with in-plane bending moments applied at both ends is approximately solved using the complex variable technique. Complex stress functions corresponding to the applied bending moments are superposed with those due to the disturbance of the crack to satisfy the governing boundary equation. The conformal mapping function devised to transform the contour surface of a circular arc crack to a unit circle is then substituted in the boundary equation to facilitate the evaluation of Cauchy integrals. In this way, the complex stress functions due to the crack disturbance are determined and the stress intensity factors are calculated through a limiting process to give their explicit forms. Eventually, the geometric functions for the variation of the stress intensity factors on account of the crack shape are plotted as a function of the curvature of a circular-arc crack.

A Criterion for Combination Rule in Flaw Assessment of Parallel Surface Cracks

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Masayuki Kamaya
Keyword(s):  
Stress Intensity ◽  
Structural Reliability ◽  
Crack Depth ◽  
Crack Size ◽  
Multiple Cracks ◽  
J Integral ◽  
Surface Cracks ◽  
Linear Elastic ◽  
Offset Distance ◽  
Bending Load

When multiple cracks approach one another, the stress intensity factor and J-integral value change due to the interaction of the stress field. Since the changes in these parameters are not always conservative in structural reliability evaluations, the interaction between multiple cracks should be taken into account. Section XI of the ASME Boiler and Pressure Vessel Code provides a flaw characterization rule for interacting multiple cracks. In Section XI, adjacent cracks are replaced with a coalesced single crack when the distance between the cracks is less than half of the crack depth. However, the criterion for the offset distance is given as an absolute value, although the magnitude of the interaction depends on the crack size. In the current study, an alternative criterion for the offset distance was examined. Linear-elastic and elastic–plastic analyses were performed for interacting semicircular and semi-elliptical surface cracks by the finite element method under a tensile or bending load. The change in the stress intensity factors and J-integral values due to the relative spacing of cracks was investigated. Based on the relationship between the magnitude of the interaction and the relative position of the cracks, the allowable ctriterion for the offset distance was discussed.

Buckling Characteristics of Floating Roof Pontoons in Aboveground Storage Tanks Subjected to Bending Load in Two Directions

2008 ◽  
Author(s):  
Shoichi Yoshida ◽  
Kazuhiro Kitamura
Keyword(s):  
Large Diameter ◽  
Bending Moment ◽  
Bottom Plate ◽  
Storage Tanks ◽  
Buckling Strength ◽  
Linear Elastic ◽  
Structural Problems ◽  
Oil Storage ◽  
Bending Load ◽  
Shell Finite Element

The 2003 Tokachi-Oki earthquake caused severe damage to aboveground oil storage tanks due to liquid sloshing. Seven single-deck floating roofs had experienced structural problems as evidenced by sinking failure in large diameter tanks at the refinery in Tomakomai, Japan. The pontoons of the floating roofs might be buckled due to circumferential bending moment during the sloshing. The content in the tank was spilled on the floating roof from small failures which were caused at the welding joints of pontoon bottom plate by the buckling. Then the floating roof began to lose buoyancy and submerged into the content slowly. The authors had reported the buckling strength of the pontoons with and without ring stiffeners subjected to circumferential bending load in the previous papers. This paper presents the buckling strength of the pontoons subjected to both circumferential and radial bending load. The axisymmetric shell finite element method is used in the analysis. Linear elastic bifurcation buckling analysis is carried out and the buckling characteristics of the pontoon with and without ring stiffeners are investigated.

scholarly journals Impact of the Weld Geometry on the Stress Intensity Factor of the Welded T-Joint Exposed to the Tensile Force and the Bending Moment

2015 ◽  
Vol 11 (2) ◽  
pp. 103-109
Author(s):  
Jelena M. Djoković ◽  
Ružica R. Nikolić ◽  
Ján Bujňák
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Fracture Mechanics ◽  
Intensity Factor ◽  
Tensile Force ◽  
Bending Moment ◽  
Linear Elastic ◽  
Weld Geometry ◽  
Axial Tensile ◽  
The Impact

Abstract In this paper it is analyzed the welded T-joint exposed to the axial tensile force and the bending moment, for determining the impact of the weld geometry on the fracture mechanics parameters. The stress intensity factor was calculated analytically, based on the concept of the linear elastic fracture mechanics (LEFM), by application of the Mathematica® programming routine. The presence of the weld was taken into account through the corresponding correction factors. The results show that increase of the size of the triangular welds leads to decrease of the stress intensity factor, while the SIF increases with increase of the welds’ width. The ratio of the two welded plates’ thicknesses shows that plate thicknesses do not exhibit significant influence on the stress intensity factor behavior.

Developing a Strength Analytical Method of a Thin-Walled Steel SHS Beam by Combine Theory of Plastic Mechanisms and Non-Linear Elastic

2013 ◽  
Vol 746 ◽  
pp. 428-433
Author(s):  
Andi M. Kadir ◽  
Dedi Priadi ◽  
Eddy S. Siradj ◽  
Harkali Setiyono
Keyword(s):  
Analytical Method ◽  
Compressive Load ◽  
Bending Moment ◽  
Hollow Section ◽  
Linear Elastic ◽  
Non Linear ◽  
Thin Walled

The research objective is focused in developing a strength analytical method of a thin-walled steel square pipe (Square Hollow Section/SHS) affected by the interaction of concentrated-compressive load and bending moment. This strength analytical method is based on two different approaches, namely plastic mechanisms and elastic theories. This is called the method of cut-off strength. In this research, it has also been carried out to test the strength of the investigated beam under the interaction of concentrated-compressive load and bending moment. In order to essess the accuracy of the analytical method developed, estimate data of this method is also verified by comparing it to the actual one measured from experiments. The verification indicated that the estimated data, on average, deviates from the experimental one by 5 %.

Pull-Out Performance of T-Stub End Plate Connected To Concrete Filled Thin-Walled Steel Tube (CFTST) using Lindapter Hollo-Bolts

2018 ◽  
Vol 15 (1) ◽  
pp. 59
Author(s):  
NAZRUL AZMI AHMAD ZAMRI ◽  
CLOTILDA PETRUS ◽  
AZMI IBRAHIM ◽  
HANIZAH AB HAMID
Keyword(s):  
Limit Load ◽  
Steel Tube ◽  
Limit States ◽  
End Plate ◽  
Pull Out ◽  
Pullout Load ◽  
Thin Walled ◽  
Stub End ◽  
Concrete Filled Steel Tubes ◽  
Ultimate Limit

The application of concrete filled steel tubes (CFSTs) as composite members has widely been used around the world and is becoming popular day by day for structural application especially in earthquake regions. This paper indicates that an experimental study was conducted to comprehend the behaviour of T-stub end plates connected to concrete filled thin-walled steel tube (CFTST) with different types of bolts and are subjected to pullout load. The bolts used are normal type bolt M20 grade 8.8 and Lindapter Hollo-bolt HB16 and HB20. A series of 10 mm thick T-stub end plates were fastened to 2 mm CFTST of 200 mm x 200 mm in cross-section. All of the specimens were subjected to monotonic pull-out load until failure. Based on test results, the Lidapter Hollo-bolts showed better performance compare to normal bolts. The highest ultimate limit load for T-stub end plate fasten with Lindapter Hollo-bolt is four times higher than with normal bolt although all end plates show similar behaviour and failure mode patterns. It can be concluded that T-stub end plate with Lindapter Hollo-bolt shows a better performance in the service limit and ultimate limit states according to the regulations in the design codes.

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