Vehicle-bridge Coupling Vibration Analysis Based On Coupled Equation

China is in its peak period of bridge construction,which has greatly promoted the development of China's economy and brought great convenience to people's lives.Most of the bridges in our country are constructed of simply supported beams,so it is very important to study the simple supported beam.But in the process of urbanisation,CFST tied arch bridges have been widely used in practical engineering for its merits such as strong spanning capacity,beautiful structure in recent years.It is of great significance to study the impact effect of the CFST tied arch bridge.This paper firstly introduces several common analysis methods of vehicle bridge coupling.and compared several commonly used analysis method with the coupling equation method under smooth road and irregular road conditions to analyzes the advantages and disadvantages of various methods and verify the applicability and reliability of the coupled equations in all cases.Then,the vehicle bridge coupling dynamic response of different vehicle models through simple supported beam and simplified tied arch bridges analyzed by the method of coupling equations.Results showed that:(a)from force model?1/4 vehicle model?1/2 vehicle model?whole vehicle model,bridge displacement responseis increasingly obvious;(b)the irregularraod condition has significant impact on midspan displacement of the bridge,the lower the grade of pavement,the greater the displacement response in the middle span of the bridge.Then,influence of road grade,vehicle speed,vehicle weight,suspension stiffness,tire stiffness parameters on the highway simply supported beam driving comfort and griping ability are studied.The results showed that:(a)the minimum contact force decreases with the increase of vehicle speed,which decreases not that much;(b)with the increase of vehicle speed,the mean square acceleration of vehicle vertical vibration increases first,then decreases and then increases,then decreases and lastly increases(C)with the increase of weight,the vertical vibration acceleration mean square value first decreased and then increased;(d)the change curve of the minimum contact force is opposite to the acceleration mean square value.That is,the smaller the contact force,the greater the acceleration mean square value,the lower the driving comfort.Finally,the CFST through tied arch bridge is studied as an example of vehicle bridge coupled vibration,comparison and analysis of the influence of road irregularity and vehicle speed,vehicle number,vehicle spacing parameters on impact factor of the bridge and derrick.The results show that:(a)the lower the grade of the pavement,the greater the impact factor of the derrick,the bigger the impact factor of the end derrick;(b)with the increase of the speed,the impact factor of the bridge increases first,then decreases and lastly increases.Influence of velocity on short derrick more severely than long derrick;(c)3 cars are recommended to use to calculate the impact factor of the derrick,1 cars to calculate the impact factor of the bridge;(d)considering the influence of the impact factor of the derrick and the impact factor of the bridge,suggest the vehicle distance is the bigger the better.