Research On The Dynamic Response And Damage Mechanism Of Train Station Building Frame Structure Under Train Impact Load

In recent years,with the rapid development of China railway high-speed,the railway stations as an important part of railway high-speed,also meet unprecedented construction speed.The railway stations,which known as the "City Gate",most use the online-style:trains across the building.If the train derailed and hit the elevated station structure,It may lead to damage the station structure,or even collapse,and resulting in huge casualties and property damage.As the elevated station was a large number of built up with the rapid development of high-speed railway in recent ten years,and currently there is still a lack of research on impact about the train station structure.Therefore,as the train derailment hit the station background,the dynamic response and the failure mode and mechanism of the train collision station are studied based on the LS-DYNA software.The main research results of this paper are as follows:(1)The structure of the typical elevated station is selected,the finite element model of train-station house structure is established,and analyze the dynamic response of the structure under different impact speed and different impact position.The analysis shows that the column damage process is basically the same when the train is impacting the frame structure differently at the same speed.The greater the impact velocity,the sooner the peak time of the impact force,the impact force Peak is linearly correlated with the impact velocity.In the process of the structure column of the train collision station,the impact influence is localized,mainly concentrated in the column and adjacent components.(2)The failure mode of the structure under impact is summarized.Under the influence of different velocity impacts,the frame structure mainly shows two kinds of failure modes:local damage and overall deformation damage.Local damage:The damage of the structure column in the collision area and the adjacent column top node due to the shear effect of trains is mainly embodied in the local shear failure,bending failure or bending failure of the structure column,and the plastic deformation is produced around the top node.Overall deformation damage:the structural deformation and displacement caused by the force of the train passing through the node to the upper structure during the collision.Including the structural translational displacements caused by impact,the vertical collapse deformation caused by the failure of the hit column.(3)The mechanism of structural resistance under collision loads was analyzed by extracting internal forces.The analysis shows that when the train impact station is Fang Zhu,the structure column has obvious arch effect mechanism in the initial stage of small deformation,and the stronger the axial constraint of the column top,the greater the axial pressure,the more obvious the arch effect;The resistance of catenary mechanism in large deformation stage.The advocate for the top structure is shared by the axial pressure in the adjacent beams parallel to the impact direction.(4)A method and process for evaluating the impact resistance of frame structures are presented.Aiming at the local damage characteristics,a quick evaluation method of damage area index is proposed.For the deformation of the whole displacement,the structural displacement angle is proposed to evaluate the damage of the structure.The former can reflect the impact resistance of the local components,which can react to the lateral collapse ability of the whole structure.At the same time,the evaluation process and design suggestion of the impact resistance performance of the station structure are given.