Impact Analysis On Anti-collision Of Polyurethane-steel Sandwich Plate System For Round Ended Pier

With the rapid development of China 's economic construction,bridges has become more and more,in addition,the progress of navigation technology conditions,so that the speed of the vessel within the navigation speed is also rising,thus,the probability of collision with the bridge also increases,and ship–bridge collision accident will seriously affect the bridge operation and service life,and even lead to the catastrophic consequences of the destruction of the bridge and victims die,thence,the research of ship collision and collision avoidance facilities is significant in the future bridge construction project.In this context,this thesis summarized the existing research results of ship bridge collision,reviews the characteristics of various types of anti-collision devices,utilizes the steel-polyurethane sandwich structure with excellent fatigue resistance advantages,and propose a new type anti-collision box of steel-polyurethane sandwich structure.Based on explicit transient nonlinear finite element analysis,using ABAQUS software to simulate the whole process of bridge collision,with parametric analysis;studing the anti-collision performance of the more common end-shaped pier and its anti-collision device,and puts forward the relevant measures to improve the structural crashworthiness and energy absorption effect,the main research work is as follows:To gain the current research situation of bridge anti-collision,summarizes the design concept of ship-bridge collision,the calculation method of ship-bridge collision,and the summary of bridge anti-collision facilities.It reviewed and summarized the history and research overview of steel-polyurethane sandwich structure,and the classical calculation theory of steel-polyurethane sandwich and the application in the field of anti-collision.The basic theory and key technology in numerical simulation of ship-bridge collision were introduced;discussed the elastic-plastic model about steel strain rate sensitivity,constitutive model of rubber hyperelastic material and the approach of deal with the influence of fluid movement when ship collision on the finite element model;Combined with predecessors on the sandwich plate of the theoretical research and dynamic impact experiments to verify the sandwich plate modeling method of rationality.The construction of the anti-collision box and its principle of anti-collision were discussed;established three dimensional analysis model of ship,anti-collision box and piers by ABAQUS software,and simulated the dynamic process of a 500 t river ship collision;The crashworthiness of the crash box was calculated and analyzed under the impact of the ship including frontal crash and flank crash;the numerical simulation results showed that the steel-polyurethane sandwich anti-collision pontoon absorbed the 71% ship's impact kinetic energy with the relative rigidity of the bow and anti-collision box and greatly weaken the impact force of pier;The box twists the bow easily,reserves most of the ship kinetic energy in the flank crash to prevent further damage to the collision;calculated and analyzed the impact process of collision avoidance pontoon at different ship collision speed,and the influence of ship collision velocity on the energy absorption and the impact force of the pier were discussed,and verified the energy absorption effect of the anti-collision box;Parameter sensitivity analysis about steel-polyurethane sandwich plate thickness and rubber fender hardness were given,and analyzed the influence of the change of structural stiffness on the box crashworthiness.