Comparison of Unstiffened and Ring Stiffened Large Diameter Flexible Steel Pipe Response to Handling, Transportation, Backfilling and Traffic Loads

2002 ◽  
Author(s):  
Dominic D. P. Trebicki ◽  
Mark C. Webb ◽  
Paul A. Smulders
Keyword(s):  
Large Diameter ◽  
Steel Pipe ◽  
Traffic Loads

Burring Process and Fracture Criterion of Large Diameter Steel Pipe

2020 ◽  
Vol 846 ◽  
pp. 139-145
Author(s):  
Shinichi Nishida ◽  
Daichi Uematsu ◽  
Naoki Ikeda ◽  
Kyohei Ogawa ◽  
Makoto Hagiwara ◽  
...  
Keyword(s):  
Shear Stress ◽  
Fracture Criterion ◽  
Maximum Shear Stress ◽  
Large Diameter ◽  
Branch Pipe ◽  
Fem Analysis ◽  
Equivalent Strain ◽  
Steel Pipe ◽  
Experimental Result ◽  
Forming Limit

This paper describes finite element method analysis (FEM analysis), results of burring processing of large diameter steel pipe and fracture criterion in burring process of large diameter steel pipe. In this study, the pipe is the 150A SGP pipe with a diameter of 165.2 mm and a wall thickness of 5 mm. The pipe is used for a plant as a flow channel of gas and liquid. A burring process of pipe is generally for forming the branch. The burring process is achieved by drawing of die from prepared hole. And the branch pipe is welded to the formed pipe. This process has some problem. One is the forming limit of pipe, and the other is needed to machining the end surface to be welded. Therefore, in this study, the forming limit of SGP pipe was estimated by FEM analysis of burring process. The parameters used for criteria for forming limit are the maximum shear stress and the equivalent strain. As a result of comparing the analysis result and the experimental result, the forming limit of the 150A SGP pipe was estimated that the maximum shear stress is 350 MPa and the equivalent strain is around 0.8.

Evaluation of Residual Stresses Induced by Repairs to Small Diameter Stainless Steel Pipe Welds

2015 ◽  
Author(s):  
Trevor G. Hicks ◽  
William R. Mabe ◽  
Jason R. Miller ◽  
John V. Mullen
Keyword(s):  
Stainless Steel ◽  
Residual Stresses ◽  
Large Diameter ◽  
Small Diameter ◽  
Steel Pipe ◽  
Limited Information ◽  
Diameter Pipe ◽  
Stainless Steel Pipe ◽  
Lower Magnitude ◽  
The Impact

Residual stresses within stainless steel pipe welds may cause or exacerbate in-service cracking. Significant investigative efforts have been devoted to the examination of piping residual stresses in large diameter piping using both finite element modeling and experimental techniques, but limited information is available for small diameter piping. Even less information is available for small diameter piping welds which have been repaired or re-worked during initial fabrication. This investigation used both experimental methods and analytical modeling to assess the impact of repair welding during initial fabrication on the residual stresses along the inner diameter (ID) of small diameter pipe specimens. The investigation showed that tensile axial residual stresses were located in the heat affected zone (HAZ) along the ID of the pipe specimens adjacent to regions which were excavated and re-welded. Such repair welds were also shown to markedly increase the magnitude of the tensile axial residual stresses for weld configurations which otherwise had lower magnitude residual stresses.

Field Trials of Suction-Assisted Installation of Circular Steel Pipe Cofferdam in Silty Sand

2020 ◽  
Author(s):  
Jae-Hyun Kim ◽  
Zhenhua Xin ◽  
Ju-Hyung Lee
Keyword(s):  
Large Diameter ◽  
Test Site ◽  
Field Trials ◽  
Offshore Structures ◽  
Silty Sand ◽  
Steel Pipe ◽  
Sheet Pile ◽  
Construction Costs ◽  
Inner Diameter ◽  
Column Foundation

Abstract The cofferdam is the temporary barrier to stop the flow of water from a construction site work such as a support column foundation at a river or offshore. It allows for working in the dry condition when the construction is done adjacent or within the waters. However, it is a major cause of delays and increased construction costs because additional works are required to stop the water flow. Recently, in order to overcome the limitations of the conventional cofferdam methods such as sheet pile or caisson tube cofferdams, a large-diameter steel pipe cofferdam method has been proposed which can be installed quickly using suction installation method. The steel pipe cofferdam method is characterized in that the top-lid of the steel pipe is located above the sea level in order to use it as a water barrier, unlike conventional suction buckets where the whole structures are submerged. In this study, the circular steel pipe cofferdam with a 5 m inner diameter was fabricated and the installation tests were conducted on silty sand at the Saemaguem test site. During the experiment, variations of suction pressure and inclination of the steel pipe cofferdam were measured and post-analyzed. This study verified the new steel pipe cofferdam method and confirmed that the suction installation method can be successfully used for various purposes on the offshore structures.

Increasing Precision of Batch Pipe Forming Method Using Burring and Ironing of Large Diameter Steel Pipe in FEM Analysis

2020 ◽  
Vol 2020.28 (0) ◽  
pp. 420
Author(s):  
Daichi UEMATSU ◽  
Kyohei OGAWA ◽  
Tatsuhir ONIZUKA ◽  
Shinichi NISHIDA
Keyword(s):  
Large Diameter ◽  
Fem Analysis ◽  
Steel Pipe
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