Numerical Simulation Of Collision Resistance Of Ship Fender Structure

In the process of ship berthing,the ship and the wharf have a direct effect,which causes the structural dynamic response of the hull and the hull,which is easy to cause the plastic deformation of the hull structure and the damage of the hull structure,and affect the safety of the ship.How to intuitively simulate the interaction process between ships and docks,identify the potential dangerous elements in the process of dynamic berthing,and put forward the control method of the safe ship berthing is a complex three-dimensional dynamic non-linear scientific problem,which will help to improve the berthing safety of ships and have important guiding significance for the safe operation of ships.In this thesis,taking the dynamic contact collision problem of ship and wharf interaction as the starting point,establishing a 3 D finite element numerical analysis model.The display dynamic method is used to simulate the dynamic process of mutual contact between ships and docks under different conditions,The dynamic change and distribution of stress,deformation,momentum and energy of the hull and guard structure are obtained,the influence of different factors on the safety of ship and guard structure is analyzed,and the evaluation and restriction methods of safe berthing are proposed.The main research contents of this thesis are as follows:(1)With small high-speed ships as the research object,the three-dimensional ship-guard-dock integration model was established with PATRAN software,and the explicit dynamic method in ABAQUS as the calculation tool.To simulate the dynamic process of contacting between ship and wharf at the initial berthing speed of 2(1028 mm/s)and 4(2056 mm/s),the dynamic changes of the stress strain,momentum and interaction force of the hull and the guard structure are obtained.(2)Review the literature,study the dynamic process of "contact-detachment" between ships and docks in different guard structures,and establish nonlinear numerical models with four different structural forms: D,square,V and mixed type.The calculated initial berthing speed is 2 sections,obtaining the dynamic change and distribution of stress strain,momentum and berthing load of the hull and bolting structure,and making suggestions for the design of bolting structure.(3)Research and analysis of different factors on the safety of ships and guard structure,and different initial berthing speeds.Therefore,studying the dynamic influence of different berthing speeds on berthing.Energy conversion,berthing speed,interaction force between ship and wharf,guard deformation and stress change are obtained,and the assessment and restriction method of safe berthing are proposed from these perspectives.(4)The influence of the surrounding fluid in the process of ship berthing was not considered in the above studies.Therefore,combined with the flow-solid coupling theory,the flow field element is added to the established finite element numerical model of ship-guard-dock integration to study and analyze the situation of the hull berthing in the flow field.To simulate the dynamic process of contact between ship and wharf at the initial berthing speed of section 2 and section 4,and to obtain the dynamic change and distribution of ship momentum and the contact and detachment.And get the motion distribution of the surrounding fluid.Compared with the fluid-free model,it is concluded that: At the initial speed of 2 knots,the force exerted by the dock was reduced by 11%.At an initial speed of 4knots,the force affected by the dock was reduced by 36%.