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China Ocean Engineering

, Volume 31, Issue 2, pp 192–201 | Cite as

Structural safety assessment for FLNG-LNGC system during offloading operation scenario

  • Zhi-qiang Hu
  • Dong-wei Zhang
  • Dong-ya Zhao
  • Gang Chen
Article
  • 44 Downloads

Abstract

The crashworthiness of the cargo containment systems (CCSs) of a floating liquid natural gas (FLNG) and the side structures in side-by-side offloading operations scenario are studied in this paper. An FLNG vessel is exposed to potential threats from collisions with a liquid natural gas carrier (LNGC) during the offloading operations, which has been confirmed by a model test of FLNG-LNGC side-by-side offloading operations. A nonlinear finite element code LS-DYNA is used to simulate the collision scenarios during the offloading operations. Finite element models of an FLNG vessel and an LNGC are established for the purpose of this study, including a detailed LNG cargo containment system in the FLNG side model. Based on the parameters obtained from the model test and potential dangerous accidents, typical collision scenarios are defined to conduct a comprehensive study. To evaluate the safety of the FLNG vessel, a limit state is proposed based on the structural responses of the LNG CCS. The different characteristics of the structural responses for the primary structural components, energy dissipation and collision forces are obtained for various scenarios. Deformation of the inner hull is found to have a great effect on the responses of the LNG CCS, with approximately 160 mm deformation corresponding to the limit state. Densely arranged web frames can absorb over 35% of the collision energy and be proved to greatly enhance the crashworthiness of the FLNG side structures.

Key words

collision FLNG LNGC numerical simulation model test side-by-side offloading cargo containment system 

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Copyright information

© Chinese Ocean Engineering Society and Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  • Zhi-qiang Hu
    • 1
    • 2
  • Dong-wei Zhang
    • 2
    • 4
  • Dong-ya Zhao
    • 2
  • Gang Chen
    • 3
  1. 1.State Key Laboratory of Hydraulic Engineering Simulation and SafetyTianjin UniversityTianjinChina
  2. 2.State Key Laboratory of Ocean EngineeringShanghai Jiao Tong UniversityShanghaiChina
  3. 3.Marine Design & Research Institute of ChinaShanghaiChina
  4. 4.Nantong COSCO KHI Ship Engineering Co. LtdNantongChina

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