• Title/Summary/Keyword: 천공스트레인 게이지법

Search Result 2, Processing Time 0.017 seconds

An Experimental Study on the Residual Stress Distribution at Circumferential Welds in Pipes (파이프 원주방향 용접부의 잔류응력분포 특성에 관한 실험적 연구)

  • Namkoong, Jae-Gwan;Hong, Jae-Hak
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.8 no.1
    • /
    • pp.41-49
    • /
    • 1991
  • A knowledge of the resdual stress distribution at circumferential weldments can normally increase the accuracy of a fracture assessment in pipe line. In this paper, we present the measurements about the residual stress distributions at three kinds of circumferential butt welded pipes using the holl drilling strain gage method. By this experiment, we have obtined the following characteristics. At the inner surface of the pipe region near the center line of welding is under high tensile residual stress. However, as the distance from the center line of welding increases, the tensile component decreases and finally becomes compressive residual stress at region far away from the center line of welding. The longitudinal residual stress at the outer surface is compressive regardless of the diameter of pipe and the circumferential stress is changed from compressive to tensile as pipe diameter increases. The results also demonstrate that the residual stress is mainly caused by self-restraint bending force in the pipe welding.

  • PDF

A study on the residual stresses in circumferential welds of the pipes (파이프 원주방향 용접부의 잔류응력 연구)

  • 남궁재관;홍재학
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.15 no.2
    • /
    • pp.693-702
    • /
    • 1991
  • The existence of residual stress in the circumferential butt welded pipes is one of the most important problems concerning stress corrosion cracking in service. In this paper, the residual stress distributions in three kinds of circumferential butt welded pipes were measured by the hole drilling strain gage method and calculation using finite element method is performed and its results are compared with the experiments. At the inner surface of the pipe region near the center line of welding is under high tensile residual stress. However, as the distance from the center line of welding increases, the tensile component decreases and finally becomes compressive residual stress at region far away from the center line of welding. The longitudinal residual stress at the outer surface is compressive regardless of the diameter of pipe and the circumferential stress is changed rom compressive to tensile as pipe diameter increases. The results also demonstrate that the residual stress is mainly caused by self restraint bending force in the pipe welding.