Fatigue Strength Assessment Of Typical Spots In LNG Bunker Vessel And Study On Influence Law Of Fuelling Parameters

LNG,as an efficient,green and clean low-carbon energy source,has become the first choice for future marine energy in the world.LNG bunker vessel,as a new type of mobile filling method for LNG fuel,is loaded with-163 Centigrade liquid.In order to avoid the damage of hull structure strength,it must be able to withstand the stress caused by temperature load for a long time.Therefore,it is of great significance to carry out the fatigue strength evaluation analysis of LNG bunker vessel and the simulation analysis of transient temperature field during filling process and the study of the influence law of parameters.The main contents of this paper are as follows:(1)The status quo of LNG vessel’s consumption and demand,structural characteristics,research meaning and background are briefly described.The research and development status of fatigue strength and thermal stress of LNG ship at home and abroad are expounded.(2)The structural strength of LNG filling vessel is calculated and analyzed.Using MSC.Patran/Nastran,the finite element model of the hull section structure of LNG bunker vessel is established and the structural static analysis is carried out.Based on the calculation results of the hull structure strength,the deformation and stress of the hull under 28 different working conditions are analyzed,and the strength of the hull structure under each working condition is checked to meet the requirements.(3)According to the simulation model of temperature field calculation of LNG bunker vessel,the steady temperature field and thermal stress of LNG bunker vessel under low temperature and high temperature are calculated and analyzed respectively,and the temperature and stress distribution of the main components of the vessel under corresponding ambient temperature are given.(4)Calculate and analyze the strength of LNG bunker vessel with temperature load,and check whether the structural strength of the hull meets the requirements under different working conditions.Referring to CCS "Guidelines for Fatigue Strength of Hull Structures",the fatigue strength of typical spots in LNG bunker vessel with temperature load is evaluated and analyzed by hot spot stress method of finite element analysis after partially refining the finite element model of cabin section.(5)Explore the rule of parameter influence in the process of LNG filling vessel with filling operation.Based on the results of the transient temperature field with filling operation,the thermal stress simulation of the cold cabin structure is carried out,the relationship between the temperature distribution characteristics and thermal stress is established,and the influence law of the filling speed on the thermal stress is given,which provides support for the design of the cold cabin structure.