Research On Dynamic Response Of Ship Bridge Collision

Intensive study of the ship-bridge collision theory to decrease the Ship-bridge collision incidents and serious consequences caused by the collision incidents has much more theory significance and realistic significance. On the basis of the collision theory and potential energy variation functional principle , the analysis theory and computation method for ship-bridge collision considering bend, shear, torsion, the effect of soil–pile and the effect of superstructure of bridge act on pier are established. In this dissertation, the main contribution is as follows:(1) Based on the collision theory and equivalent boundary principle, a mass-spring model was built to simulate ship-bridge eccentric collision. This model takes ship as a mass point, use a linear spring to simulate relationship between ship loading and deformation.(2) Based on the potential energy variation functional principle of Hamilton, the lateral transient vibration equation of bridge piers with different shapes of the solid pier section and the hollow pier section was deduced by considerring the bending deformation, shear deformation, torsional deflection. The differential equation of the collision system, the boundary conditions were transformed with Laplace transformation, the analytical solution of the stress wave in frequency domain was educed. And then the solution in frequency domain was inversed by using the mathematical software of Matlab on the base of Crump inverse transformation. Finally, the dynamic response in time domain was obtained.(3) Compared with the calculation which was solved by using finite element software of ANSYS/LS-DYNA, which proved this method was correctly and accurately, and it also shows that this method are more rational and applicable than the criterion.(4) The mass of ship, velocity, contact flexibility, the bending stiffness and torsional stiffness of bridge act on the impact force were analyzed by using ship-bridge impact calculation theory in this dissertation, and by considering the eccentricity, the simplified computational formula of the Maximum impact force was deduced.(5) The ship-bridge impact model of continuous rigid bridge was simplified appropriately, which the superstructure was simulated by an anti-push spring, a bending spring, a torsion spring. The pile-soil was simulated by an equivalent model of the group of piles, and then the computational mechanics model and its boundary constraints were established.According to the research, computational mechanics model of ship-bridge eccentric collision was built by considering different boundary conditions. Meanwhile, based on the equivalent boundary principle, a new method to solve ship-bridge collision problem was provided, and impact force and each dynamic response of structural can be obtained through this method.