The Design And Simulation Analysis For FRP Anti-collision Pontoon Of Chongqing Jialing River Huanghuayuan Bridge

The ship-bridge collision, a complex problem of nonlinear dynamics, is thenonlinear dynamic response process that absorbs, transforms and dissipates the hugecollision energy in a short time through the deformation and crushing of the structuresor components in collision region. Due to the multiple and complex influence factors, itis not easy to make a precise analysis of ship-bridge collision process, while nonlinearfinite element technology could be adopted to simulate the entire collision process andto get the results in line with the demands of engineering practice.On base of the reference and sorting of domestic and international literature dataabout ship-bridge collision, the paper is to discuss the defects existing in the basictheory of external mechanism study, to analyze several current study methods aboutinternal mechanism of ship-bridge collision and summarize respective advantages anddisadvantages, and to comparatively analyze the advantages and disadvantages ofvarious protection systems themselves and the application conditions in the perspectiveof protection mechanism and protection performance. In combination of the pierprotective device design of Chongqing Jialing River Huanghuayuan Bridge, the paper isto apply the fiber reinforced polymer (FRP) with such characteristics as light mass, highstrength, low modulus and full elasticity for the design of FRP anti-collision pontoon,and to put forward and make comparison and selection among three design proposals.The paper is to present the advantages and prospects of FRP anti-collision pontoon inbridge anti-collision engineering by explaining its structure, working principle andefficiency mode. ANSYS/LS-DYNA software is applied to respectively simulate tenconditions that1600-ton weight bulk ships collide with four FRP anti-collision pontoonswith different stiffness at both directions, from which we can get the impact force andtime history curve of energy under each working condition as well as the time historycurve of energy transformed and dissipated of various components of the pontoon inprocess of collision. Through the analysis and comparison of the data from theseworking conditions, we could get the following:①The anti-collision pontoon is able to effectively withstand collision without beingpenetrated, protecting the pier from damage;②The outer and inner lining energy-dissipation cylinders are able to effectively extendthe collision time and consume the collision energy; ③FRP anti-collision pontoon is a good choice for energy-dissipation, whoseenergy-dissipation efficiency accounts for34%～47%of the total energy;④Realize the design concept that the flexible energy-dissipation of the thin-wallenergy-dissipation cylinder is dominant while the energy-dissipation of theperipheral box is subsidiary;⑤FRP anti-collision pontoon behaves well to lower the compact force peak value,being able to lower25.83%～55.67%;⑥After comparison and analysis of the FRP pontoons with four different elasticmodulus in light of lowering compact force and energy-absorbing effect, the FRPanti-collision pontoon with10GPa elastic modulus is chosen to be protection deviceof bridge piers, which is able to lower36.69%～50.36%of compact force under frontand flank crash conditions compared with those with no pontoons, satisfying thedesign requirements.