Dynamic Response Analysis Of Collision Between Ship And Fender-Pile System

Flexible berthing piles are common berthing facilities,so it is of great significance to study the collision between ships,berthing piles and fenders for the layout optimization of berthing piles.In this paper,the nonlinear finite element models of ships,fenders,cluster piles and wharf platforms are established by using ANSYS/LS-DYNA module,and their dynamic responses to collision are discussed.In order to explore the influence of cluster pile arrangement on the impact response characteristics,a nonlinear numerical model of ship-to-ship cluster piles was established,and the effects of pile diameter,pile spacing and pile number on the impact response results were compared and analyzed.The results show that the increase of the pile diameter increases the stiffness of the pile body,reduces the impact time and the pile body stress,and increases the impact force and slip energy;the pile spacing is within four times the pile diameter,and the change of the pile spacing has a limited impact on the cluster piles;When the pile body volume is the same,the more piles,the higher the structural flexibility,the longer the collision time and the longer the pile top displacement,the lower the impact force,but the greater the stress,the easier it is to damage,and the double pile cluster pile has the best performance.In order to explore the influence of fender factors on the collision response characteristics of ship-cluster piles,a ship-to-ship cluster pile(with fenders)model was established,and D-type fenders and super-arch fenders were respectively installed on ships of different tonnages.The dynamic response process of the ship time model.When the cluster piles are installed with super arched fenders,they often separate from the ship after the initial impact,and then collide with the second time;the energy absorbed by the fenders is limited,and the energy absorption ratio of the cluster piles increases with the increase of the tonnage of the ship.The energy absorption ratio is finally stabilized at about 1:9.The energy transfer between the fender and the cluster pile takes time,and the increase and decrease of the energy of the two are not synchronized;the arched fender and the D-type fender transmit energy to the rear cluster pile through multiple deformations,and the energy transferred in a single time is limited.In comparison.the D-type fender has more single passes.In order to explore the influence of the wharf platform on the collision response characteristics of the ship-cluster piles.a model of ship-berth piles-dock platform(with cylindrical fenders installed in front of the platform)was established,and the distance between the cluster piles and the wharf platform(hereinafter referred to as the spacing)was discussed.),the influence of ship tonnage on the collision response;the difference between the displacement of the pile top and the deformation of the fender is kept at a certain value.and the two reach the peak deformation at the same time;when the distance is small and the large-tonnage ship collides,the fender and the platform play a major role in attracting Energy effect;with the increase of the spacing,the proportion of energy absorption between the fender and the platform gradually decreases.If the spacing is too large.the cluster piles will not be able to contact the fender and the platform;the distance between the cluster piles and the platform fender should be adjusted according to the tonnage of the berthing ship..so that both can give full play to the energy absorption effect;it is more reasonable to choose a distance of 0.2m for a 3000t ton ship.In order to contrast with the model of ship-cluster pile-dock platform(with cylindrical fenders installed in front of the platform),the energy distribution of the impact process and the influence of the fender type on the collision response are discussed when fenders are installed in front of the cluster piles.A model of ship-by-ship cluster piles(with fenders installed in front of the cluster piles)-dock platform(with cylindrical fenders installed in front of the platform)was established.It shows that the installation of fenders can prolong the impact duration by about 15%(arch)and 41%(D type),reduce the residual kinetic energy of the ship by about 13%(arch)and 30%(D type).and reduce the cluster pile by 30%.(arch)and 50%(D-type)energy absorption,transform the impact force from a larger peak to multiple smaller peaks,which is more conducive to berthing stability.