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복합하중에 의한 천연가스 배관의 파손확률 평가

Failure Probability Assessment of Natural Gas Pipeline under Combined Stresses

  • 백종현 (한국가스공사 가스연구원) ;
  • 장윤찬 (한국가스공사 가스연구원) ;
  • 김익중 (한국가스공사 가스연구원) ;
  • 김철만 (한국가스공사 가스연구원) ;
  • 김영표 (한국가스공사 가스연구원)
  • 투고 : 2020.05.29
  • 심사 : 2020.07.23
  • 발행 : 2020.08.31

초록

신뢰도 기반 평가법은 천연가스배관의 기하학적 형상 변화, 기계적 특성, 하중변화 및 운영조건을 평가 인자로 사용하여 천연가스배관의 건전성 평가 관리의 신뢰도를 향상시킬 수 있다. 구조신뢰성 평가 시 배관의 파손확률은 외부하중에 대한 배관재료의 저항성과의 관계에 의해 평가된다. COMREL 프로그램을 사용하여 내압, 열응력 및 굽힘응력과 같은 복합응력에 의한 천연가스배관의 파손확률을 평가했다. 천연가스배관의 파손확률 평가 시 매설깊이는 1.5~30m, 차량바퀴하중은 2.5~20톤, 온도차는 45℃, 운전압력은 6.86MPa 그리고 토양밀도는 1.8kN/㎥를 사용하였다. 천연가스배관의 파손확률은 Von-Mises 응력 기준에 의해 복합응력 하의 최대허용응력 기준으로 평가하였다.

The structural reliability assessment can be used to improve the reliability in the asset integrity management of the pipeline by using a geometric variation, mechanical characteristics, load change and operating condition as evaluation factors. When evaluating structural reliability, the failure probability of the natural gas pipe is evaluated by the relationship of the resistance of the pipe material to external loads. The failure probability of the natural gas pipe due to the combined stresses such as the internal pressure, thermal stress and bending stress was evaluated by using COMREL program. When evaluating the failure probability of the natural gas pipe, a buried depth of 1.5 to 30 m, a wheel load of 2.5 to 20 ton, a temperature difference of 45℃, an operating pressure of 6.86MPa, and a soil density of 1.8 kN/㎥ were used. The failure probabilities of the natural gas pipe were evaluated by the Von-Mises stress criterion as the maximum allowable stress criterion under the combined stresses.

키워드

참고문헌

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