Research On Ship Impact Force Atlas Of Independent Bridge Piers In Inland Rivers

With the vigorous development of the country’s inland waterway navigation,out-ofcontrol operations of inland waterway ships hitting wading bridge piers have become one of the important risks affecting the safety of inland waterway navigation.In order to solve this problem,whether it is the design of the anti-collision ability of the bridge structure,the production design of the anti-collision device or the safety consideration of ship construction,it is necessary to have a numerical estimate of the ship collision force.With reference to the domestic and international situation,there is always a lack of systematic results to guide the research on ship-bridge collision risk.In order to fill the gap in this part,and also to save more manpower,material resources and time when conducting ship collision risk research in the future,and to provide convenient method guidance for assessing ship collision force.In this paper,the numerical simulation method is first verified by the energy dissipation effect test of the anti-collision facilities of the Songpu Third Bridge,and the stiffness of the bridge pier model is checked and calculated.Then the full-scale 1000 t flat bow type,3000 t pointed bow type,5000 t and 8000 t bulbous bow type are established.The model,the vertical arc-shaped pier model,and the irregularly variable-cross-section arc-shaped pier model are used to simulate a total of 140 working conditions.During the period,the pier model,ship tonnage,ship collision speed,and ship collision angle factors that may affect the ship collision force are carried out.Dynamic response analysis,and finally using large-sample numerical simulation calculation data and empirical formula calculation values for reference,draw the inland river pier bridge ship collision force map.The basic conclusions and corresponding results of this research are as follows:(1)The comprehensive analysis of the energy dissipation effect test results of the Matsuura Third Bridge’s anti-collision facilities and the ABAQUS numerical simulation collision results verify the rationality of the finite element software in the collision simulation process,the contact,the setting of the boundary conditions,and the establishment of the material constitutive model,which can be used The finite element method studies collision problems.(2)Using the calculation formulas of ship collision force at home and abroad,the ship collision force under various working conditions in the sample interval of this study was calculated,and the trend analysis of Tupu ship collision force was carried out in combination with the numerical simulation results.(3)Using ABAQUS,a full-scale model of 1000 t flat bow,3000 t pointed bow,5000 t and 8000 t bulbous bow ships was established.On the basis of the steel structure of the outer deck of the ship,the internal ribs,stiffeners and supporting structure were in accordance with the actual size.Construct.Two types of piers,standard vertical arcshaped piers and irregular arc-shaped piers,were established for construction,and the model stiffness matching verification was performed on the test piers.(4)Research on the dynamic response of the results of finite element numerical simulation: using vertical arc-shaped piers to study the collision force,the calculation results are more stable;the tonnage of the ship and the collision speed are the most important factors affecting the force of the collision,and both are related to the calculation of the collision force.The value is positively correlated,and there is an obvious linear growth relationship;the impact force of a forward impact(90°)is always the highest,followed by an impact angle of 60°,and the impact force is the lowest at 45° and 30°collisions;the energy dissipation and internal The speed that can be increased is faster.The bow collision depth under the condition of the collision angle is greater than the collision depth produced during head-on collision,and the bow damage is the most serious under 60° collision.(5)An inland river pier bridge ship collision force map was drawn.The ship collision force value was selected to take into account the safety estimated in the actual application of the project.The forward impact force of the ship was used as an important factor of the map.In addition,the map covers: 1000t-8000 t ships,2-8m/s ship collision speed and collision depth divided by the time coefficient,using the known ship tonnage and ship collision speed,the estimated value of ship collision force and collision depth can be queried.This map has innovative value for the research of ship collision with bridge.