| The collision between ship and bridge occurring in a short period of time is aseries of complex dynamic response process involving the nonlinearity of material,geometry, contact and movement, which can directly lead to the damage and evencollapse of the whole bridge. It also can become a serious threat to the safety ofpeople’s life and property and a huge obstacle to the water transportation. With thedevelopment of transportation industry, ship-bridge collision frequently occurs andhas been paid more and more attention and been researched. Based on contact theory,fluid-structure coupling algorithm and finite element method, this paper analyzed thedynamic response of the pier and its variation behavior after ship collision withLS-DYNA software, regarding the practical engineering accident as back ground. Theinfluence of impact parameters on bridge pier’s dynamic response was also discussedin this paper. The analysis of the whole damage evolution, deformation, stressdistribution and the whole bridge’s collapses revealed the mechanism of local damageand collapse of the whole continuous girder bridge after ship’s impact.All the works of this paper and the main conclusions are summarized as follows:(1) Three-dimensional finite element models of the ship, bridge pier and thewhole bridge were built based on ANSYS. The pile-soil interaction was alsoconsidered and the viscous-elastic artificial boundary was firstly applied to theproblem of ship-bridge collision.(2) Three kinds of ship-pier collision calculation models were establishedincluding: not considering fluid influence, additional mass model, and fluid-structurecoupling model. After comparing and analyzing the characters of system energy,variation of collision force, penetration depth of ship bow, displacement, internalforce and stress distribution, it was found that fluid medium participated in the energyexchange and made a little influence on the dynamic response of the pier, but it caneffectively reduce the collision damage of the ship. Additional mass model willslightly exaggerate the pier structure’s dynamic response, but the error is relativelysmall and the more important is that it can approximately consider the influence offluid with wasting little computing resources. (3) The changes of water level, collision angle, speed and tonnage of the shipwere also discussed in this paper. Pier’s dynamic responses caused by different impactconditions were analyzed and the main conclusions were drew as follows. With theincrease of water level, peak value of collision force and pier’s internal forceaccordingly increase, but it has a little influence on pier’s horizontal displacement.When the ship frontally impact the pier, peak value of collision force, displacement ofpier and its internal force are maximum. The collision force and the shear force of pieraccordingly increase with the increase of ship speed, but the bending moment reduced.It showed the deformation of pier has a trend of the transition from overall bending toshear deformation. With the increase of deadweight tonnage of the ship, the peak ofcollision force, displacements of pier and pile cap increased, but the change ofdisplacement is more significantly influenced by the deadweight.(4) The partial collapse process of a continuous girder bridge was simulated inthis paper. Three stages of the whole calculation process respectively are acting load,ship-bridge collision and collapse. The simulation reappeared the collapse of thecontinuous girder bridge after ship collision. By analyzing the changes ofdisplacement, distortion, stress, internal force and the mechanism of partial ruptureand collapse, it was found that losing stability of the impacted pier and the tractionforce between adjacent spans caused by the excessive deformation of the box girderare the main causes of the whole bridge’s partial collapse. |
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