Research On Vehicle-bridge Coupling Vibration Of Continuous Rigid Frame Bridge With Composite Box Girder With Corrugated Steel Webs

Compared with box girder bridges with concrete webs,corrugated steel web composite box girder bridges are widely used in bridge construction in recent years because of their many advantages.Its structural form has evolved from the original simple beam to the present continuous beam bridge,continuous rigid frame bridge,cable-stayed bridge,composite structure,etc.Among them,the continuous beam bridge and continuous rigid frame bridge of corrugated steel web composite box girder are most widely used.For this new structure,many scholars have done in-depth research on its static performance and achieved fruitful results.However,the research on its dynamic performance is still insufficient.At present,the research on the dynamic performance of composite box girder bridges with corrugated steel webs is mainly aimed at the launching of simply supported girder bridges,followed by continuous girder bridges,and for continuous girder of composite box girder with corrugated steel webs.Few literatures on the study of dynamic performance of bridges.As the span of continuous rigid frame bridges with corrugated steel webs and box girders is increasing,the traffic flow and the load capacity of modern traffic have increased greatly.The dynamic response of the bridge type under vehicle loads is obvious.In order to ensure the safety and comfort of driving,it is necessary to study the dynamic performance of continuous rigid frame bridges with composite box girder with corrugated steel webs.This paper takes the Xiaoshagou Bridge of Beihuan Road,Lanzhou City as the engineering background,and studies the dynamic characteristics and vehicle-bridge coupled vibration response of continuous rigid frame bridges with composite box girder with corrugated steel webs.The main work and conclusions are as follows:(1)The principle and method of dynamic analysis of bridges are summarized,and the application of finite element method in dynamic analysis of structures is emphasized.The7-DOF two-axis space vehicle model and the 9-DOF 3-axis space vehicle model were selected,and the equations of motion of the vehicle and the equations of motion of the vehicle-bridge coupled vibration system were established.(2)The finite element software ANSYS was used to establish the finite element model of space bridge of continuous rigid frame bridge with corrugated steel web composite box girder.Its dynamic characteristics were analyzed and compared with the dynamic characteristics of continuous rigid frame bridge of concrete web.The vertical stiffness of the continuous rigid frame bridge with corrugated steel webs is slightly less than that of continuous rigid frame bridges with concrete webs,and its transverse bending stiffness and torsional stiffness are significantly lower than those of continuous rigid frame bridges with concrete webs.(3)The space full-bridge finite element model established by ANSYS was introducedinto the multi-body system dynamics software UM,and a vehicle model was established in UM to generate different levels of road irregularities.(4)The relevant parameters were set to analyze the dynamic response of the continuous rigid frame bridge with composite box girder with corrugated steel webs in terms of vehicle speed,bridge irregularities,vehicle load and vehicle axle number.It has been found that the increase in vehicle speed,the reduction in the level of bridge irregularities,and the increase in vehicle load will aggravate the vehicle-bridge coupling vibration of continuous rigid frame bridges with composite box girder with corrugated steel webs.The effect of the three-axle vehicle on the coupled vibration of the vehicle axle is greater than that of the two-axle vehicle.The coupled vibration of vehicle-bridge of continuous rigid frame bridge with corrugated steel web composite box girder is more obvious than that of continuous rigid frame bridge with concrete web.