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Flaw Assessment on an Offshore Structure using Engineering Criticality Analysis

ECA 기법을 이용한 해양구조물의 결함 평가

Kang, Beom-Jun;Kim, Yooil;Ryu, Cheol-Ho;Ki, Hyeok-Geun;Park, Sung-Gun;Oh, Yeong-Tae
강범준;김유일;류철호;기혁근;박성건;오영태

  • Received : 2015.05.26
  • Accepted : 2015.11.18
  • Published : 2015.12.20

Abstract

Offshore structure may be considerably vulnerable to fatigue failure while initial flaw propagates under cyclic loading, so crack propagation analysis/fracture/yield assessments about initial flaw detected by NDT are necessarily required. In this paper, case studies have been conducted by flaw assessment program using engineering criticality analysis (ECA) approach. Variables such as flaw geometry, flaw size, structure geometry, dynamic stress, static stress, toughness, crack growth rate, stress concentration factor (SCF) affected by weld are considered as analysis conditions. As a result, the safety of structure was examined during fatigue loading life. Also, critical initial flaw size was calculated by sensitivity module in the developed program. The flaw assessments analysis using ECA approach can be very useful in offshore industries owing to the increasing demand on the engineering criticality analysis of potential initial flaws.

Keywords

Flaw assessment;Fracture mechanics;Crack propagation analysis;Initial flaw;BS7910

References

  1. Nho, I.S. Nam, Y.Y & Lee, H.S., 1993. Structural Safety Assessment of Independent Spherical LNG tank(2nd report) –Fatigue Crack Propagation Analysis Based on the LBF Theory-. Transactions of the Society of Naval Architects of Korea, 30(4), pp.74-82.
  2. Kim, K.S. Shim, C.S. Kwon, Y.B. Ko, H.S. Ki, H.G. & Viswanathan, K.K., 2008. A Study of Crack Propagation and Fatigue Life Prediction on Welded Joints of Ship Structure (II). Journal of the Society of Naval Architects of Korea, 45(6), pp.679-687. https://doi.org/10.3744/SNAK.2008.45.6.679
  3. Kim, C.W. Nho, I.S. & Do, K.S., 2002. A Study on the Fatigue Crack Propagation Analysis Using Equivalent Stress Distribution. Journal of the Society of Naval Architects of Korea, 39(2), pp.61-68.
  4. Jeon, Y.C. Kim, Y.I. Kang, J.K. & Han, J.M., 2001. A Study on Fatigue Life Prediction of Welded Joints through Fatigue Test and Crack Propagation Analysis. Journal of the Society of Naval Architects of Korea, 38(3), pp.93-106.
  5. British Standard Institution (BSI), 2005. Guide to methods for assessing the acceptability of flaws in metallic structures. BS7910.
  6. Yoon, K.J & Kim, M.H., 2013. Engineering critical assessment of material for IMO independent tank Type-B LNG tank structure. The Annual Autumn Conference, Ulsan, 7-8 November 2013, pp. 800-804.
  7. Yim, S.J. & Byun, T.U., 1993. The Integrity Assessment Method of Initially Cracked Structural Component by Reliability Analysis. Transactions of the Society of Naval Architects of Korea, 30(2), pp.161-176.

Acknowledgement

Grant : 해양플랜트 특성화대학