Ansysis Of Vehicle-bridge Coupled Vibration For Long-span Suspension Bridge With Finite Element Model Updating Under Random Traffic Flowing

The vehicle-bridge coupled vibration is the interaction result of the vehicle system and the bridge structure system. The former research limits much in the decideing traffic flowing, and the studying vehicle model mainly is the two axes and the three axle vehicle. But the actual traffic flowing have very strong randomness in the bridge surface, such as the two axes, the three axes, four axes, five axes and six axes and so on. In addition there is some certain difference between the bridge structure finite element model and the actual structure, further reduces the computed result precision, thus the former research results have some limitation in promoted application. Therefore this article based on the studying of the random traffic flowing for some highway bridge, with the aid of the model revision method, some long span suspension bridge is taken as the studying case, some research are carried on the the influence of the vehicle-bridge coupled vibration, which manifests in the following aspects.(1) Some studying was carried on the random distribution rules of speed, distance between vehicles, types and weight. The simulation procedure of stochastic vehicles stream is programmed with the Matlab procedure. A contrast research is carried among different forecast methods for vehicle current capacity. And the combination forecast is determined as the optimum prediction method. It is perfectly used to forecast the real-time highway bridge vehicles current capacity. Through a statistical analysis to the highway bridge vehicles current capacity, a general statistical parameter of common vehicles flowing is obtained and a corresponding stochastic parameter database is established for the fist time. Several of stochastic vehicles stream model are produced incidentally.(2) For the fist time, an updating method for sub-structure finite element model is proposed based on the sensitive parameter analysis. With the proposed method, the revision for a finite element computation model of Siduhe long span suspension bridge is carried successfully, which lays a realible foundation for the following vehicle-bridge coupled vibration research.(3) With the twenty one, the twenty five and the twenty nine freedom degrees system simulated the four, five and six axis vehicles model separately for the fisrt time. Based on the existing 13 degree of freedom two axis vehicles and the 17 degree of freedom three axis vehicles, has consummated the computation model system of the traffic random flowing for typical vehicles and enhanced the computation precision of the vehicle model. Based on VB language, vehicle-bridge coupled vibration procedure BDANS is established, which can be used to analysis the random traffic flowing, and the interface is realized among BDANS and the random traffic flows simulation procedure, as well as the large-scale finite element computational procedure ANSYS. Finally this procedure is validated through the analysis of the simple substance quantity spring system beam-model and some great span continual rigid frame dynamic load experiment.(4) Based on the BDANS and the ATVFM procedure, some long span suspension bridge is taken as the studying case. A systematic research is firstly carried on the effect of the sixteen common vehicle types, vehicles rigidity, damping and driving condition for dynamic response and impact of the bridge structure. At the same time, the influence and rules of the vehicle-bridge coupled vibration is further studied with the changing of bridge structure parameters, such as the stiffness of main cable, suspension cable, centre buckle, stiff grider and main tower. The research conclusions discovered the impact factor are not sole to increase along with the structure rigidity increases or reduces. The different structure spot correspondence impact factor also has the big difference, the same structure spot endogen impact factor of the force and the displacement also have some difference. Forthmore according to the basic principle of the extreme value extrapolated method, the basic step is delivered, and the biggest dynamic response and the impact coefficients, which produced from the stochastic vehicles stream to the bridge structure under different surface roughness condition, are obtained.The conclusion in this paper might build a reliable foundation for the flowing research of vehicle-bridge coupled vabriation and provide a beneficial reference for the construction and maintenance of the similar bridge in the future.