Research On Risk Assessment Of LNG Ship Colliding With Marine Platform

During carrier voyage, marine accident is inevitable to avoid. Due to the impact of theviolent, the structure of LNG ship is violently shaken, easily lead to leaks of LNG ship. Theleakage in the air forms heavy gas clouds rapidly, if the leakage had some fire origin in theburning explosion range, the combustion will take place immediately. Most likely toupgrade into fire, explosion, further breakage of the hull structure will aggravate, whichWould not only pose a threat to the safety of personnel and equipment, and also theenvironment. LNG ship risk assessment can scientifically predict the probability ofaccidents and accident consequences. In the field of marine and ocean engineering, it hasaroused widespread concern, mainly because the technology can deeply reflect the risksessence. It is significant to improve the safety of LNG carrier’s operation system, andprovide reliable theoretical basis for the design to reduce the leakage of LNG carrier.Based on the theory of risk assessment, this paper identifies the risk of LNG carrier’sleakage, calculates the rate of accidents. Based on the study of fault tree analysis (FT)method, Bayesian network (BN) is used to analysis human reasons.This paper also studies the crashworthiness of LNG carrier’s side with compositesandwich structure, and puts forward measures to reduce the risk of consequences. Based onthe combination of fuzzy comprehensive evaluation (FCE) and LNG ship leakage riskassessment, studying on the multi-level fuzzy comprehensive evaluation.The work and conclusions of this paper were as follows:(1) Analyzing the research progress of risk assessment at home and abroad in oceanengineering. Setting out the theory of risk assessment, studying on risk measurements fromperson, society, environment, and exploring the risk acceptance criteria.(2) This paper has a simple introduction on the risk identification, comparing themethods of analysis, the influence of accident consequence to personnel and facilities areanalyzed, and some measures to control the risks are put forward.(3) Based on the binomial distribution theory, forecasting the LNG ship annualcollision accident probability. Reference to risk analysis method of DNV passing shipscolliding with offshore platform, computing programs are written to calculate the collisionsprobability of the vessel at different angles. Based on the study of fault tree analysis (FT)method, Bayesian network (BN) is used to analysis human reasons, and puts forward the measures to reduce accident consequences.(1) This paper put forward the composite sandwich structure, The original double sidestructure of a LNG carrier was replaced by this structure. The structure is simulated by thesoftware MSC.Dytran. Compared with the traditional steel structure, composite sandwichstructure has obvious advantages. Results show that sandwich is lightweight high strength.It can be improved the crashworthiness performance by optimizing the structure. It’s aneffective measure to reduce the risk.(2) Based on the theory of fuzzy comprehensive evaluation and analytic hierarchyprocess, the introduction of leak gas quantity,character,weather Douglas, LNG ship shapeand personnel status (distance risk source distance) and other risk factors, calculating theinfluence factors (parameters), studying on the multi-level fuzzy comprehensive evaluation.