Experimental Study On The Finite Element Model Correction Method Of PC Composite Box Girder Bridge With Corrugated Steel Webs

Corrugated steel web PC composite box-girder bridge is a new type of bridge composite structure,which properly combines concrete and steel materials,making full use of the characteristics of different materials,and has the advantages of economy,high efficiency,convenient construction and light weight.At the same time,it also improves the prestressing efficiency,reduces the amount of prestressed steel,and improves the structural stability,load capacity,and material efficiency.With the rapid popularization of PC composite box girder bridges with corrugated steel webs,it is necessary to further study them and fully understand their characteristics.This is inseparable from a finite element model that can accurately and fully reflect the true mechanical characteristics of the PC composite box girder bridge with corrugated steel webs.At present,there are related researches on the finite element model modification methods of prestressed concrete continuous beam bridges,arch bridges,cable-stayed bridges and suspension bridges.However,the finite element modeling modification methods of PC composite box girder bridges with corrugated steel webs Less research.In order to explore the finite element model correction method of PC composite box girder bridges with corrugated steel webs,this paper proposes a finite element model correction method of PC composite box girder bridges with corrugated steel webs based on response surface method and multi-objective optimization method.The main contents of this article include:(1)Carry out static and dynamic load tests on a PC composite box girder bridge with a corrugated steel web.In the static load test,the deflection values of the test bridge under static load are obtained through symmetrical load conditions and eccentric load conditions;in the dynamic load test,the self-vibrations of the tested bridge are obtained through sports cars,jump tests and environmental wind loads.(2)Base on design drawings and material parameters,ANSYS is used to establish a solid three-dimensional finite element model for a PC composite boxgirder bridge with corrugated steel webs,and a numerical simulation test is performed on the initial finite element model based on the solid bridge static load test.The vertical third-order natural frequency of the finite element model is obtained by using the block Lanthos method.Finally,the deviation between the obtained numerical simulation test results and the actual bridge tested results are compared.(3)Parametric significance analysis of the design parameters of the finite element model of the PC composite box-girder bridge with corrugated steel webs is used to obtain design parameters that have a significant effect on the vertical third-order natural vibration frequency of the structure and use them as parameters to be modified;The experimental combination design is carried out through the experimental design method,and the response surface proxy model is established by response surface fitting using independent variables and response values;the single objective function is constructed using the response surface proxy model to optimize the parameters to be modified,and the modified design parameters are solved.The input finite element model is used to modify the finite element model.The static and dynamic load tests were performed on the modified finite element model,and the deviation between the test results of the finite element model before and after the correction and the results of the real bridge test were compared.(4)In order to make the revised finite element model accurately and comprehensively reflect the true mechanical characteristics of the bridge structure,a multi-objective optimization method and a particle swarm evolution algorithm are introduced,and the initial finite element model is modified in combination with the response surface method.Obtain the design parameters that have a significant impact on the static load displacement of the measurement point through saliency analysis and use them as the parameters to be modified;obtain the response surface proxy model of the finite element model by experimental design and response surface fitting;use the response surface proxy model Construct multiple objective functions,and use the improved particle swarm evolution algorithm to search for the Pareto optimal solution of the objective function;select the compromised optimal solution from the Pareto optimal solution as the correction result of the parameters to be modified and input the finite element model to achieve Modifications to the finite element model.A numerical simulation test of static and dynamic loads was carried out on the modified finite element model,and the deviation between the simulation test results and the actual bridge test results was compared.