Strength Study Of Heavy-lifts Carried By Inland-river Deck Freighter

From the perspective of economic cost,a large number of goods are usually transported by water.However,the environmental loading of waterway transportation is relatively adverse and complex,which leads to the problem of ship strength unneglectable.The thesis takes the inland-river deck cargo ship as the research object.The local strength of the ship carrying cargoes is analyzed by using the finite element method(FEM).Based on the analysis of the local structure in the process of cargo transportation,the thesis puts forward corresponding suggestions to improve the local strength of the ship.First,the hull shape is built by CATIA,the 3D engineering design software;the finite element model of partial cabin is established by ANSYS,the finite element software.According to the requirements of the specification,the corresponding boundary conditions are set.Second,the local strength of deck freighter is studied.By using the finite element software,the static analysis carried out,the actual working condition of the ship simulated,the nephogram of stress and deformation of the ship is calculated,in order to verify whether the ship can meet the requirements of safe navigation under the maximum loading state.Last but not least,in order to overcome the deficiency of local strength of the ship,the plate thickness will be increased from the point of design,and the dunnage will be laid in the view of navigation,the local strength of the ship is enhanced effectively.Besides,the ultimate weight per unit carrying area of the deck cargo ship is calculated to guide the safe navigation of the ship.The technical and economic benefits of ships are also enhanced by making improvements in local structure of the ship from the perspective of navigation.The innovative achievements of the thesis are as follows:(1)The curved shape of hull is established based on CATIA.The plate and profile sizes is given by ANSYS.The three-dimensional cabin model of deck freighter is also built.Then the technological difficulty in modeling process and the specific solutions are presented.(2)By using the FEM,the local strength of cargo carried by the target ship is studied,and calculates the target ship’s ultimate load.In order to solve the problem of insufficient local strength of ship,some approaches are proposed from the perspective of navigation,laying dunnage on the deck.(3)From the practical point of view of ship design,the method of local optimization of the inland-river deck cargo ship is proposed.To be specific,in order to improve the local strength of the ship,the thickness of the transverse bulkhead will be increased in size 2mm.In addition,the size of the pillar will be changed from φ108×6 to φ90×6 to optimize the structure of the ship.