Research On Dynamic Response Evaluation And Impact Force Prediction Method Of Ship-Bridge Collision

With the rapid development of transportation industry,ship routes are becoming more and more intensive,and the number of cross-river and cross-sea bridges is.increasing year by year,resulting in the increasing probability of ship-bridge collision accidents.Ship-bridge collision accidents may cause serious consequences,such as ship sinking,bridge collapse,personal casualty,obstruction of waterway traffic,environmental pollution caused by fuel leakage.Therefore,it is of great significance to carry out research on ship-bridge collision to ensure the safety of ships and bridges.Firstly,the key problems of ship-bridge collision finite element method are discussed,and numerical simulation of ship-bridge collision typical condition is analyzed.Secondly,a variety of influencing factors are selected to make up multiple working conditions to analyze the influence of each factor change on the ship-bridge collision,and the statistical analysis method is introduced to study the correlation between each factor and the impact force of the ship-bridge collision.Finally,combining the numerical simulation and artificial neural network method,the impact force prediction model of the ship-bridge collision is established.The main work of this dissertation is outlined as follows:(1)This paper analyzes the ship-bridge collision accident and its research status,and puts forward the significance of the research.Then it discusses the solution method of ship-bridge collision and the advantage of using nonlinear finite element analysis method to solve the problem.(2)Establish the finite element model of 6600DWT cargo ship and bridge pier,select the appropriate material model and failure criterion,correctly define the contact settings,and discuss the difference of the impact of the additional water quality method and the fluid-solid coupling method to simulate the impact of the fluid.Then the typical calculation mode of finite element analysis is established.(3)The whole process simulation of typical ship-bridge collision mode is completed by using nonlinear finite element software.The laws of energy conversion,collision damage and motion change in the process of collision are analyzed.And then a new method of fast and accurate assessment of ship damage is proposed.(4)Three influencing factors of ship load,impact speed and collision angle are selected,and multiple working conditions are set up to study the influence of each factor on ship-bridge collision force,damage deformation of ship and dynamic response of bridge pier.The maximum impact force of 50 working conditions is obtained by calculating the combination of three influencing factors one by one,and the correlation between the influencing factors and the maximum impact force is studied by using the partial correlation analysis method.(5)Based on the artificial neural network and finite element analysis,the prediction model of ship-bridge collision force is established on the input of ship load condition,impact speed and collision angle.BP neural network and Elman neural network are used to build the surrogate model,so that the impact force prediction method with high accuracy is obtained.