Research On Energy Dissipation Mechanism Of Bridge Pier Anti-collision Device Based On Spring-damping Model

The buffer type anti-collision device protects bridge from collision of ships by three main ways: cushioning collision,turning the ship head and absorbing energy.It has a very realistic engineering significance that the use of anti-collision devices in the bridge piers to mitigate the hazards of bridge ship collisions.However,there is less research and application of anti-collision devices for inland river barges.The purpose of this paper is to study the energy dissipation mechanism of anti-collision device in barge collision.First,the effect of the parameters change on the protection performance was explored by establishing the spring-damping simplified model of the anti-collision device.Then,the effect of collision avoidance was verified by the FEA of barge impact at various angles.Finally,the mechanism of energy dissipation is further analyzed by changing the contact shape characteristics of the anti-collision device.The main research contents and achievements of this paper is outlined as follows:(1)Analysis of key parameters of spring-damping model of anti-collision device.The refined finite element model for 500 DWT barge and the spring-damping simplified model of anti-collision device was established.And the dynamic FEA of collision dynamics between barge and different elastoplastic stiffness parameters anti-collision device was carried out.Then,the impact force,impact penetration and energy relation curves were compared and analyzed.The results showed that the parameters such as spring stiffness and maximum allowable deformation have a far-reaching influence on the protection performance of the anti-collision device.Moreover,the proposed value of the relevant parameters of the anti-collision device was proposed.(2)Analysis of energy dissipation mechanism of EPSD in anti-collision device.The constitutive relation of energy dissipation steel components was calculated by establishing the mechanical calculation model and the FEA model of EPSD.Furthermore,established the spring-damping model of anti-collision device based on the constitutive parameters of EPSD,and analyzed its dynamic response against barge impact.The results showed that arranging EPSD reasonably can play the role of deformation and energy dissipation effectively in the anti-collision device.(3)Researching on the protective mechanism of anti-collision device against barge collision at different angles.Carried out the dynamic FEA of 500 DWT barge with different Angle impacting on bridge pier and anti-collision device,and compared the impact force,barge motion process and energy transformation form.The results showed that the anti-collision device has protective effect on barge collision at all angles.In the slanting collision situation,the friction between contact surfaces become a key element.That is to say,the anti-collision device can reduce the friction between barge bow and pier,change the direction of barge,and separate the barge from the bridge pier as soon as possible.Ultimately,barge would take part of the collision kinetic energy away and reduce the damage risk of the bridge structure.(4)Analysis of the influence of the shape of the contact surface on the energy dissipation mechanism of the anti-collision device.The collision process and dynamic response of anti-collision device and rigid pier which were impacted by 500 DWT barge with two kinds of contact surfaces were analyzed.The results showed that the impact force is related to the shape of the contact surface between the barge bow and bridge pier.The collision process can be delayed to further reduce the impact force and can make the barge bow cooperate with the anti-collision device to dissipate collision energy by Changing the contact surface shape of the anti-collision device into an arc shape.