Mooring system fatigue analysis for a semi-submersible

OCEAN ENGINEERING

卷:156

Article

Xue, Xutian¹  Chen, Nian-Zhong²  Wu, Yongyan³  Xiong, Yeping⁴  Guo, Yunhua^1,5 

[1] Newcastle Univ, Sch Engn, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England

[2] Harbin Engn Univ, Coll Shipbldg Engn, Harbin 15001, Heilongjiang, Peoples R China

[3] Aker Solut Inc, 3010 Briarpk Dr,Suite 500, Houston, TX 77042 USA

[4] Univ Southampton, Fac Engn & Environm, Southampton SO17 1BJ, Hants, England

[5] Wuhan Univ Technol, Sch Energy & Power Engn, Wuhan 430063, Hubei, Peoples R China

关键词: Semi-submersible;    Fatigue assessment;    T-N curves;    S-N curves;    Fracture mechanics (FM);   

DOI  :  10.1016/j.oceaneng.2018.03.022

来源: Elsevier

【 摘 要 】

T-N curves, S-N curves, and fracture mechanics (FM) based mooring system fatigue analyses for a semi submersible are presented. Stress ranges are calculated based on the tension ranges of mooring lines subjected to the combined loading process induced by the motions of wave frequency (WF) and low frequency (LF). A comparison between T-N curves, S-N curves, and FM based mooring fatigue analyses for the semi-submersible is made and the results show that the fatigue lives predicted by the three approaches are in general comparable if the safety factors suggested by API and DNVGL are considered in the T-N and S-N curves based approaches. In addition, the crown section of a mooring chain is prone to fatigue damage compared to bend and weld sections without considering the SCF. A parametric study to investigate the impact of initial crack shape, critical crack depth, and initial crack sizes on fatigue life of a mooring chain is also conducted and the results show that fatigue life of a mooring chain predicted by the FM approach is generally sensitive to initial crack shape and initial crack sizes, however, it is relatively insensitive to the critical crack depth.

【 授权许可】

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