Research On The Influence Of Dynamic Characteristics Of Long Span Curved Beam Bridges

The terrain of our country is complex and changeable,and two-thirds of the total area is covered by mountains,especially in the west and southwest.The terrain is dangerous and the ravines are vertical and horizontal.Long-span curved beam Bridges are widely used in highway construction in the southwest of our country because they can better meet the traffic demand in the complex terrain environment.When the vehicle passes the bridge,the bridge structure vibrates violently due to the vehicle's dead weight and vibration,and the vibration of the bridge caused by vehicle disturbance will react on the vehicle.The interaction between the vehicle and the bridge is the vehicle-bridge coupling force.With the increase of vehicle load?vehicle speed?bridge span and bending degree,the interaction between vehicles and bridges was becoming more and more serious.Therefore,it is of great practical value to study the dynamic characteristics of long-span curved beam Bridges.This paper is a part of Shanxi Province Science and Technology Research Project "research on characteristics of long-span continuous beam bending bridge based on the action of sensitive elements"(No.201803D31076).Based on a long-span curved beam bridge,the project analyzed the dynamic response of curved beam bridge under the action of shifting force.The vibration model of uniform moved constant force through simply supported beam bridge was established and the equation of uniform interaction force was derived.Based on the transient dynamics theory of ANSYS,the second development of APDL was carried out to realize the dynamic response of the bridge,and the dynamic characteristics of the long-span curve bridge under the action of sensitive element parameters were analyzed and studied.It showed that when the driving speed was constant,the bending moment and deflection of the most unfavorable cross section of the bridge structure are not affected by the radius of curvature,while the calculated value of the torque was affected by the radius of curvature.When the radius of curvature of the bridge is constant,the critical section deflection,bending moment,and torque of the bridge structure are more uniformly affected by the driving speed,and the vehicle speed increases first and then decreases.The research results reveal the variation rule of dynamic response of the bridge structure under the action of different sensitive elements and reveal the impact coefficient of the key section parameters of the bridge through comparative analysis.By studying the dynamic characteristics of long-span curved beam Bridges,this paper provided a reference for the development of the dynamic characteristics evaluation system of Bridges in the later period,A method for obtaining the fundamental frequency of similar curved beam Bridges was also provided.