Numerical Simulation Of Ship Collision Prevention Of Yangtze River Trunk Bridge And Experimental Study On The Performance Of Protective Device

The development of water transportation has led to a sharp increase in the risk of ship collision with bridges in the channel.Due to the large scale of bridges crossing the Yangtze River channel,once a ship bridge collision accident occurs,the consequences are serious,resulting in bridge damage or even collapse,resulting in casualties and severe economic losses.Although the existing bridge anti-collision facilities can resist ship collision and play a protective role,there is still a lack of indepth research and quantitative analysis on the protective performance of anti-collision devices.In this paper,the anti ship collision problem of Yangtze River Trunk Bridge and the performance test method of protective materials are studied.The main research work includes the following parts:(1)Through the integrated modeling method,select the representative ship type of the Yangtze River trunk line,establish a high-precision finite element model after reasonable simplification,discuss the definition of material setting and contact type in the finite element model,analyze the dynamic response after the collision between the ship and the rigid wall,and analyze the parameters with the variables of ship impact velocity and the section type and size of the hit pier,and discuss its influence on the ship impact force,Draw the impact force time history curve and impact force depth relationship curve of several representative ship types of the Yangtze River trunk line.(2)The circular simplified bow model is established,the collision test between the simplified bow and the reaction wall is carried out by using the large mass horizontal impact test device,and the finite element model of the collision between the circular simplified bow and the rigid wall is established by using the general explicit finite element software LS-DYNA for numerical simulation,which is compared with the collision test results to explore the feasibility of the test device.At the same time,through parameter analysis,the equivalent stiffness control factors of the simplified bow model are changed,and its influence on the stiffness of the bow model is analyzed according to the time history curve of the impact force.(3)Establish the reduced bow model,also carry out the horizontal impact test and finite element simulation analysis,and consider using the cumulative impact method to provide greater impact load,so as to make the reduced bow structure produce greater impact depth deformation,draw the impact force impact depth relationship curve,and compare it with the simplified formula of the code.(4)Two types of standard specimens are proposed,and the response surface test design is carried out for them to explore the influencing factors affecting the protective performance of standard specimens.Through the comparative analysis of impact test and finite element collision analysis,the recommended standard specimens are given.This paper expounds the overall process of performance testing of protective materials for bridge ship collision prevention device.