Finite Element Model Updating Of Self-anchored Suspension Based On The Response Surface Method

The finite element model updating is to focus on one of the bridge health monitoring.The difference between the bridge finite element model and the real bridge mainly in the degree of dispersion of the finite element model, modeling parameter errors, simplifying assumptions and the error caused by the construction process, and these will lead to a finite element model does not accurately reflect the bridge’s true working condition. The paper regard correction of self-anchored suspension as the research object, studied the relationship among self-anchored suspension modal test data model, the finite element model and response surface model for model updating. The main research work and the results obtained are as follows:(1) The theoretical dynamic characteristics of self-anchored suspension was studied in this paper.The finite element model of Beam and plate combination structure of Mudanjiang Xi Shi Yi Tiao Lu self-anchored suspension bridge was established by Midas civil, and the dynamic characteristics calculation of the bridge first8mode shapes and natural frequencies were anlayzed for experimental modal analysis provides a theoretical reference.(2) Compared finite element analysis of dynamic characteristics with Measured modal analysis results and studied the their modes relationships.The experimental modal parameters were Preliminarily analized while the theoretical modal shapes and theoretical natural frequency were taken as reference.It is a highly effective method in identifying modal parameters.The preliminary modal parameters were checked with SSI which was publicly known more accurately. From the result of the identification, we can see that both of these methods has good recognition of the modal parameters.The measured modes shapes is basically the same to theoretical modes.But the measured modal frequencies are generally lager than theoretical frequencies.(3) Chosen the vertical and horizontal spring stiffness of the main span supports、 weight and elastic modulus of concrete as the updating parametes.Studied the model updating method of the finite element model of the self-anchored suspension based on the response surface model. Central composite test of four parameters is designed. In order to get a central composite test response, dynamic characteristics of the corresponding parameter sample values were recalculated. A significant degree of various parameters of the response surface equation was obtained from significance analysis and the response surface was fitted by the response surface equation.From the Significance analysis,we can see that the quadratic parameters of the vertical spring sitffness of the supports and the concrete weight have significant impacts on vertical bending vibration. The elastic modulus of concrete has impact on the Torsional vibration.Take the measured modal frequencies as Target control to optimize the parameters configuration. Finally, the natural frequency of the amended accuracy have improved。...