Research On The Updation Of Suspension Bridge Model Of Steel-Concrete Hybrid Beam Based On Load Test

In recent years,complex bridges of new materials,new structures,new construction technologies are created and old bridges have experienced long-term service.How to grasp the stress characteristics and behavior analysis of these bridges is a problem that must be faced in the project.The precise finite element model has far-reaching significance for the damage identification,health monitoring,structural performance evaluation and structural optimization of bridges.Based on the bridge load test,the response surface method is applied to the finite element model updating of steel-concrete hybrid beam suspension bridge.The main research work is as follows:First of all,the method in the process of finite element model updating is explored.In this paper,the uniform design method is used to determine the sample points in the finite element updating process and reduce the number of trials.The author described the application of uniform design method to model updating.The response surface method is applied to the updating of the finite element model of the steel-concrete hybrid beam suspension bridge,so as to obtain a finite element analysis model of the suspension bridge that can more truly reflect the actual state of the structure.The concept and principle of response surface method,the fitting and accuracy test of response surface function are described and explored.At the same time,the choice of parameters to be modified,the extraction of feature information,the selection of optimization methods and the determination of objective functions are explained.Secondly,combined with the engineering practice,the bridge finite element model is established and the load test is carried out.The static and dynamic information of the bridge is extracted,and whether the actual working state of the bridge is consistent with the design expectation is analyzed.At the same time,whether the bridge operation safety degree and the quality of the construction meet the requirements are determined.The technology,methods and means of bridge detection are summarized,and the problems in bridge load test are discussed.Finally,the finite element model of the bridge is updated by information gained from load test.The sample points are obtained through experimental design,and the first-order response surface and the second-order response surface are established.The static and dynamic test data obtained from the load test are combined with the first-order response surface and the second-order response surface,and the objective function is established by the difference between the measured data and the response surface.In this paper,6 objective functions are established,and two different optimization algorithms are used to optimize the parameters,and the result of parameter correction is obtained,and the optimization results are analyzed.Finally,combining the error of the initial model and the error of the updated model,the correction effect based on 6 different objective functions is analyzed and compared,and the model with better correction effect is verified.