Study On The Protective Performance Of New Anti-Collision And Interception Devices Under Ship Impact

Water transport is one of the most common modes of bulk cargo transportation,and bridge collisions often occur during ship operations.Bridge interception and anti-collision devices can effectively reduce the impact damage of runaway ships on the bridge foundation,interception and anti-collision devices are now widely used in traffic safety protection facilities of highways,railroads and waterways.With the rapid development of China’s ship business,the type of antiship collision bridge interception,collision avoidance device tends to be diverse,the mechanics of the interception device,protection performance to put forward higher requirements.However,due to the traditional interception device and anti-collision device structure is single,the application conditions are harsh,and for the protection of non-navigable holes in inland rivers not enough attention.Therefore,in this paper,the mechanical performance of the collision prevention device is studied by adjusting the cross-sectional dimensions of the floating box based on the circular surface SPS(sandwich panel structure)protection floating box and numerically simulating various ship impact conditions;a new type of throwing net type interceptor is proposed in cooperation with Xi’an CCCC Civil Engineering Technology Co.The relative optimal configuration of the lifting tower stabilizing bracket was analyzed by numerical simulation,and the interception effect of the new interception device under ship impact was studied by applying numerical simulation and compared with the interception effect of the traditional interception device,the main contents and conclusions are as follows:(1)The cross-sectional dimensions of the SPS protective floating box are adjusted,six different elliptical cross-sections of floating boxes are designed,and a full ship-protective floating box-bridge pier numerical model is established using Abaqus to verify the reliability of the model material parameters.The key quantities such as energy,stress,impact force,displacement deformation and angular velocity of the ship’s bow are analyzed,and the protection performance of the protective floating box against the bridge pier under the forward and oblique collision conditions of different cross-sectional floating boxes is discussed.Through polynomial fitting,the optimal biaxial ratio interval value for the protection performance is given.The results show that the energy absorption of the floating box increases and then decreases with the increase of the biaxial ratio,and the difference of stress peak and final angular velocity of the bow of the floating box is not obvious with different biaxial ratios,and the peak impact force and deformation of the floating box decrease with the increase of the biaxial ratio.Therefore,within a certain range,the protection performance of the floating tank shows a certain regularity with the increase of the cross-sectional biaxial ratio.(2)A new type of cast net interceptor is proposed,and the parametric analysis of the stabilizing bracket in the new interceptor is carried out using Abaqus,and the effects of the number of brackets,distribution shape,bracket curvature,and bracket cross-section type on the stabilizing bracket are analyzed.The number of brackets and structural distribution at relatively better performance were obtained.The results show that the difference between the number of brackets is 1.4% when the number of brackets is 6 and 8,the support effect is relatively better when the distribution shape is circular,the effect of bracket curvature on the stable bracket is not significant,and the longer the wing plate of I-beam section is,the better the support effect is.Through the above working conditions,the stable bracket is relatively better when the number of brackets is 6,the distribution shape is circular,the bracket is straight,and the bracket cross-section type is I-type I-beam cross-section(set in the paper).(3)The numerical model of the new type of cast net interceptor is established,and the reliability of material parameters,boundary conditions and connection methods are verified by scaled-down tests and corresponding numerical simulations.15 working conditions are established according to the factors of positive impact,oblique impact,impact point location and initial speed of the ship,and the laws of energy,displacement,velocity and impact force changes are analyzed by using Abaqus to simulate the process of ship impact on the new type of interceptor.It is verified that the new interceptor has good interception effect under ship impact.(4)Establish the model of traditional cast net interceptor and use Abaqus to simulate the process of ship impacting the traditional interceptor.By analyzing the key quantities such as energy,displacement,velocity and impact force in the collision process,the interception effects of the new and traditional interceptors under two working conditions of ship frontal collision and ship oblique collision are discussed.The results show that compared with the traditional interceptor,the volume and mass of the lifting tower of the new interceptor are reduced by17.16% and 11.99% respectively;the energy absorption rate is slightly increased;the peak displacement of the interceptor net and the peak impact force of the interceptor net are reduced by about 5%,and the ship speed is reduced more quickly.It further verifies that the new interception device has good interception effect.