Strcutural Response Analysys Of FLNG Under Sloshing And Collision Impact Scenarios

As a floated liquefied natural gas production and offloading equipment,FLNG needs LNGC to carry out the offloading and transport of liquefied natural gas.During the side-by-side offloading operations between FLNG and LNGC,the collision between the two vessels is inevitable under sudden ocean environment loads,which is a huge security threat for FLNG structures and the cargo containment system(CCS)of internal liquid tanks.This issue would be more serious when there is sloshing in the liquid tanks of FLNG.Therefore,the structural responses of FLNG and LNGC side structures and cargo containment system under collision and sloshing impact are analyzed by numerical simulation methods.In the present research,the LS-DYNA program is selected as a numerical simulation solver.Three local finite models of FLNG and LNGC are constructed for this study,including a detailed cargo containment system in the FLNG side model.According to a model test of FLNG-LNGC side-by-side offloading operations which is completed in the deep basin of Shanghai Jiao Tong University,key collision parameters are obtained from this test.Based on these parameters and possible collision situations,three typical collision scenarios are defined.To evaluate the structural responses and safety of the FLNG vessel,a special limit state is proposed based on the structural response of the LNG CCS.The whole research is divided into two parts.In the first part,the structural responses of FLNG under LNGC collisions are analyzed.This part focuses on structural responses for the CCS,the primary structural components and energy dissipation and collision forces.The second part of this study analyzed the structural strength of FLNG under collision and sloshing impacts.The results of sloshing impacts in FLNG tanks are used in this study and structural responses for the CCS under various sloshing impacts are put on attentions.The crashworthiness of FLNG structures under various collision scenarios is researched completely in this paper,which provides technical support for the evaluation of FLNG structural safety and later structural design.