Research On FDPSO Against Collision

With the depletion of the sources on earth,it is urgent to face the importance of exploring the ocean,which covers 71%of the earth.Exploring the deep ocean sources is a good opportunity for the Chinese ship building industry.Chinese ship building industry is recently rising rapidly.At this special time,what we need is to have our own high-tech products---products lick the FDPSO.FDPSO is a new type of ships which have both high-tech feature and good economy value.In addition,the first FDPSO in the world is now under construction in a Chinese company,and this is a precious study opportunity for us.Ship collision is a complicated nonlinear instantaneous process under huge impact load, which has a marked dynamic characteristic.Furthermore,the structure of collided area will exceed elastic phase rapidly,then turn into the plastic flow status,meanwhile,damage and failure such as fracture and buckling could happen.And during the ship collision,many factors can affect collision result such as the wind,wave and flow impact,the relative position and velocity and the location of the collided ship.Therefore,the mechanical analysis of ship collision is extreme complex.Many research tools and methods for ship collision analysis have been developed since Minorsky's inaugurating study in this field,including empirical method,simplified analytical method,experimental method,finite element method(FEM),and so on.At present,nonlinear finite element numerical simulation is one of the most effective methods among them.Now this method has been used in engineer work extensively.In this paper the finite element model of collision of ship and platforms was built to study the structures collision characteristics.By the research of collision simulations,we obtain the pictures about damage distortion depended time and the curve of relative between energy and distortion,crashworthiness and distortion.Based on the fluid-structure coupling method,This project created a finite element simulation module on two ships collision---a merchant ship with a bulbous bow ship and a FDPSO,and is also did the numerical simulation on the collision process.Based on the module,the study analyzed the collision characteristics of the FDPSO,gave out the simulation pictures of the damaged parts of FDPSO and the curves of energy versus collision forces,and,last but not least,discussed the factors which can influence the module,such as weight of collision ships,initial speed.