Dynamic Characteristics Analysis And Optimization Design Of New Combined Pier Anti-Collision Box

The rapid development of the economy has accelerated the development of the transportation industry,so the number of bridges across straits and rivers has gradually increased,and the number,tonnage and speed of ships on the water are also increasing.The risk of ship-bridge collisions is also increasing invisibly,and in order to protect the safety of the piers while minimizing the damage to ships and people,the installation of pier anti-collision facilities is inevitable.Based on the current anti-collision facilities,this paper proposes an FRP combined pier anti-collision box with larger impact level,wider use of water areas,more prominent anti-collision performance and service life.In the structural study of three groups of FRP combined pier collision boxes,the structure with the best anti-collision performance was determined after comparative analysis of finite element simulation results,and the optimal anticollision performance structure is optimized and designed by multi-objective optimization method,so that its anti-collision performance is more prominent and the structure is more lightweight.The main research content of the thesis is as follows:(1)The finite element model of honeycomb combined collision box and ribbed plate combined collision box was established,and compared with the round tube type combination collision box with more research.Considering the effects of ship mass,initial speed,collision angle,and collision position,the collision simulation between the ship and the collision avoidance box is conducted,and the appropriate finite element algorithm is determined.(2)The collision theory of ship bridge and the calculation method of ship collision force were summarized,and the theoretical value of impact force and displacement theoretical value under bare pier working conditions were compared and analyzed with their simulation values,which verified the correctness of the simulation results.Based on finite element simulation,the energy conversion response,impact force response,overall displacement response and impact depth response of honeycomb composite anti-collision box,round tube composite anti-collision box and rib plate composite anti-collision box are obtained.After comparing and analyzing the response results,it is concluded that the honeycomb combined collision box has the best anticollision performance.(3)Using the response surface method,ANOVA method and power coefficient method,the shell thickness of the anti-collision box and the thickness of the internal steel structure are used as the design parameters,and the maximum ship impact force,the total internal energy absorbed by the FRP combined collision box and the overall total mass are selected as the design goals,and the optimal structure honeycomb combined collision box is optimized for multiple objectives,so as to realize the optimal collision avoidance performance of the FRP combined collision box and make the structure lightweight.