Fatigue Damage Estimation for Mooring lines of Spar Platform Using System Identification Method

시스템 식별법을 이용한 스파 플랫폼 계류라인의 피로 수명 예측

  • Received : 2016.01.11
  • Accepted : 2016.06.24
  • Published : 2016.06.30


This paper presents a methodology through which the time series of the dynamic response of mooring line tension can be predicted without relying on a time-consuming nonlinear time-domain analysis. The mooring line tension for the target short-term sea states was predicted using a Hammerstein-Wiener model, a popular system identification scheme, based upon the pre-calculated motion-tension time history data for some selected short-term sea states that do not overlap with the targeted ones. The obtained mooring line tension was further processed, and a fatigue damage comparison was made between the predicted and calculated values. The results showed that the predicted time series of the mooring line tension matched the calculated one fairly well. Thus, it is expected that the methodology may be employed to enhance the efficiency of mooring line tension analysis.


Mooring tension;System identification;Fatigue life;Mooring line;Wave scatter diagram


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