The Performance Study Of New Anti Ship Collision Device For Bridge Pier

With the rapid development of the transportation business,more and morelong-span bridges which were across the river or across the sea had been put into usingor under construction. Many bridges located on the major waterways and ofen beenhitted by cruise ships, which would affect the safe operation and the service life ofbridges adversely and even leave the catastrophic potential accidents. Therefore settingthe anti-collision device on pier was an effective method to reduce the direct damage ofimpact force on the bridge structure.The ship-bridge collision was a complex nonlinear dynamic response processwhich not only involved the ship’s own motion and deformation, and also included thedisplacement and deformation of pier and anti-collision decices in a very short period oftime and under a giant impact loads. During the impact, there were a large number ofnon-linear phenomena, such as geometric nonlinearity, material nonlinearity and contactnonlinearity, etc. In the collision process, the plastic deformation, failure and hull rigidbody motion of ship,anti-collision device and pier concurred and interacted each other.Due to the complexity of the problem of ship-bridge collision, it was difficult toestablish a precise mathematical model to obtain analytical solution.So taking advantageof the dynamic combination of finite element numerical simulation software and modeltest study on dynamic stress response becomed a viable way.It could not only predictcollision-avoidance device dissipation effects, but also provide a theoretical basis for thedesign and improvement of anti-collision device.Combined with the collision project of Chongqing Huanghuayuan Jialing RiverBridge,it introduced a new anti-ship collision device—FRP anti-collision pontoon,basedon the summary of the existing ship-bridge collision research results and the investigatinof collision mechanism and analysed the entire dynamic response process of a2000tbulk carrier with3m/s velocity hitting the bridge pier with FRP anti-collision pontoonusing explicit transient nonlinear finite element technology.It studied thecrashworthiness of anti-collision pontoon. The work of this paper was as follows:①It reviewed and summarized the history and research overview of the collisionmechanical mechanism at home and abroad; it overviewed the research methodsanti-ship collision at home and abroad; it analyzed the test between ship–shipcollision and ship-bridge collision, and lay a theoretical foundation for the research work of this paper.②The basic theory and key technology in numerical simulation of ship-bridgecollision were discussed;the finite element analysis software ANSYS/LS-DYNAand post-processing software LS-PREPOST were introduced; it made a specialstudy of contact-collision, hourglass control and LS-DYNA reducing thecomputing time.③Combined with the collision project of Chongqing Huanghuayuan Jialing RiverBridge,it introduced a new anti-ship collision device—FRP anti-collisionpontoon and analysed the entire dynamic response process of a2000t bulkcarrier with3m/s velocity hitting the bridge pier with FRP anti-collision pontoonusing explicit transient nonlinear finite element technology; the entire timecourse of the collision was simulated comprehensively; the impact energy ofcollision system, impact force, the hitted depth of ship and speed, thedisplacement of the FRP anti-collision pontoon’s hitted areas, the structuraldamage and deformation of ship and the FRP anti-collision pontoon etc wereanalysed; the numerical simulation results showed that the FRP anti-collisionpontoon absorbed the52%ship’s impact kinetic energy and played a certain rolein energy dissipation and pier’s protection.④A large number of numerical simulation analyses were done for the dynamicresponse process of ship hitting the bridge pier with FRP anti-collision pontoon,the relationship between impact force and the impact velocity of the ship, ship’stonnage, the ship’s impact angle which were the three main factors was studied,the peak of impact force and the impact velocity of the ship showed a linearrelationship, the peak of impact force and the quality of ship’s tonnage showed alinear relationship, the peak of impact force and the ship’s impact angle did notshow a certain regularity, so it also needed another deeper study.⑤Discussed the basic principles of the physical model test design of anti-collisiondevices; overall structure of the scale model impact test program and full scalemodel segment structure impact test program based on the dynamic model withsimilar conditions of Chongqing Huanghuayuan Jialing River Bridge pier withFRP anti-collision pontoon were researched; the results of full scale modelsegment structure impact test program not only provided a persuasive trial basisfor achieving "energy dissipation and lower pier ship collision force50%"design expected of Chongqing Huanghuayuan Jialing River Bridge pier with FRP anti-collision pontoon, but also verified the rationality of numericalsimulation analysis method and the correctness of numerical simulation resultsin the third chapter.