Research On Performance Of UHPC Anti-collision Energy Dissipation Device

With the continuous progress and development of transportation construction,the increasingly perfect infrastructure,and the prosperity of the water industry,the probability of ship-bridge collision accidents is also increasing.The destructiveness of a ship-to-bridge accident is amazing.It will not only cause ship damage,bridge damage,or even collapse,but also cause huge losses to people’s lives and property safety and socio-economic development.In this paper,the Langhe Bridge is used as the actual engineering background.The finite element simulation software Ansys / Ls-Dyna is used to model the collision process between the UHPC anti-collision floating tank and the 500 DWT barge and the research of the bridge anti-collision device.The analysis of factors such as the maximum impact force,energy conversion relationship,maximum impact depth and speed of the ship’s bow,and the impact of the impact speed and angle of the ship on the collision effect are considered.Basis.The main research work and achievements of this paper are as follows:(1)Summarize the representative history of ship and bridge collision accidents at home and abroad and the development history and research overview of ship and bridge collision mechanics at home and abroad,and introduce the classification method of traditional bridge pier protection devices.At the same time,five kinds of ship-bridge probabilistic models and practical calculation formulas of ship-bridge collision force are listed and compared.(2)A brief discussion and analysis of the impact dynamics of the ship-bridge collision is made.The stress waves propagate under the collision,and the ship’s bow undergoes severe deformation,which then breaks down and collapses.The impact stress waves and the unloading waves generated on the structure surface interact with each other.Under the action,tensile damage occurred on the free surface of the bow.(3)The excellent mechanical properties of UHPC materials are introduced.The impact resistance and impact resistance of UHPC materials have been significantly enhanced after the steel fibers have been incorporated.A multi-compartment floating crash box was proposed with multiple UHPC-steel fiber composite beam structure sealed cabins.(4)Summarize four common concrete dynamic constitutive models,including viscoelastic constitutive model,visco-elastoplastic constitutive model,concrete damage model,and concrete cap model.Among them,the HJC model in the concrete damage model is applicable to The advantages of large strain,high pressure and high strain rate,so the HJC model was selected as the finite element simulation concrete damage model to analyze the impact process.(5)Using a 500 DWT barge to hit the pier of the Longhe Bridge as the actual engineering background,and bump the bare pier of the bridge at a speed of 4 m / s,and study the changes in the maximum impact force,energy conversion relationship,maximum impact depth,and ship speed Situation and other calculations.(6)Finite element simulations of the impact factors of the ship’s impact speed and impact angle are made,with initial sailing speeds of 2 m / s,3 m / s,4 m / s,and 5 m /s,respectively,and crosswise at the same speed.Bridge to intersection angle 0.,30.,45.,60.The UHPC anti-collision buoyant tank was impacted under the conditions of the vehicle,the collision characteristics of the anti-collision device were summarized,and the impact of the impact speed and the impact angle on the impact result was investigated.