Coupled Vibration Analysis Of Highway Bridge Based On Random Flow

Highway bridges play an important role in modern highway traffic.Various types of complex live-load effects on the bridge have been the focus of attention,and the coupling of the vehicle and bridge is one of them.Compared with the railway bridge,the highway bridges are subjected to different types of vehicles,and their main live-car flows are random,resulting in a very different coupling effect between the bridges and cars.Therefore,a reasonable assessment of the effect of random traffic on the impact of highway bridges is of great significance.Firstly,this paper introduces the theory of cellular automata simulation traffic flow,and uses the matlab program to compile a two-lane CA model.It elaborates on the selection of traffic flow related parameters,and proposes a matching with the bridge coupling program.Afterwards,this paper introduces the theory and numerical simulation methods of the vehicle-bridge coupled vibration analysis,and uses the displacement coupling method to program the ANSYS vehicle flow-bridge vibration analysis.The trigonometric series method was used to simulate the road irregularity,and the control section selection method was proposed.Next,this paper uses a six-span continuous box girder bridge as an example to establish a finite element model of "approach-bridgeapproach".Based on the measured traffic data,it analyzes its response to traffic flow under various density conditions.The effects of various factors on the flow-bridge coupling were studied.Finally,this paper discusses the calculation method of the impact coefficient under the effect of random traffic flow and compares the values of the impact coefficient in the bridge specifications of China,the United States,Japan,and Canada.The results showed that the random flow-bridge coupled numerical analysis method proposed in this paper has good applicability and practicability.Among the four factors related to traffic flow-bridge coupling,the degree of bridge deck irregularity and the vibration caused by random flow-bridge coupling The maximum speed limit restricts the passage of traffic flow and thus affects the flow-bridge coupling.The density of traffic flow is positively correlated with the degree of bridge response.The parameters of lane change in micro-traffic flow model have no direct effect on bridge response.The calculated bridge impact coefficient in this paper conforms best with Chinese norms,which verifies the rationality of Chinese norms and embodies the local conditions of each country's norms.