Dynamic Response Analysis On Vehicle-Bridge Interaction Of Box Girders In Urban Rail Transit

Rail viaduct use many box beams for larger stiffness, most currently used bridge model is established based on ANSYS, leading the model not high generic due to the special model which its parameter is not inconvenient to fix.Bridge model established straightly with beam element can not consider the lateral vibration of bridge differences along panel.Rail coupled vibration affected by many factors, it is difficult to accurately simulate the results, andit often need the field testing verification.When the vehicle speed is large, the train running stability limit is may exceeded, it will bring no comfort to the passengers.With an accurate, fast and versatile calculation procedure on vehicle-bridge interaction, it will be reference for predicting the vibration caused by emerging urban rail transit.According to the above problem, this article choose the part of Ningbo rail transit line 1 Lugang to Xujiacao with continuous beam bridge as the research object, according to the principle of potential energy is constant value, as well as "reserved seats" law,the beam segment element model is established, and the author make it compared with the finite element model of ANSYS; 31 degrees of freedom space model about vehicle model is used in accordance with the elasticity of wheel-rail contact assumed that the train and bridge model coupling iteration, use MATLAB to calculate the speed of 60 km/h bridge dynamic response; To demonstrate the correctness of the application, this paper gets field testing on the research object, that has been obtain clear regularity about the vibration of each part of the box girder components. Finally, this paper discusses the speed effect on the amplitude of the box girder vibration, and the influence of the speed of train running stability. In the process of research,this paper get the following conclusions:(1)The beam segment elementof bridge model based on the energy method can be used for coupled vibration analysis of vehicle-bridgeand the calculation method is correct, which can be used to bring a preliminary forecast of the vibration response of the new emerging urban rail transit.(2) Vehile-bridge vibration has atrend that vertical vibration affected sharper than transverse vibration in straight line when the moving speed increase.In addition, the vertical acceleration of bottom of bridgehas always maximum level, the amplitude is much greater than the webs transverse acceleration and the cantilever plate vertical acceleration,structure noise of the bridge floordeserveconcern.(3) Based on the stability criteria of the evaluation results which is more reasonable than the standard based on the maximum vibration acceleration of the evaluation results, when the moving speed reach the maximum of 80 km/h, stationarity is not beyond the limit.