Research On The Effect Of Substructure In Model Updating Hybrid Simulation Method

The model updating hybrid simulation improves the accuracy of the hybrid test by adding a process of parameter identification on the basis of the traditional hybrid test.According to the test process,it can be divided into two types: online model updating and offline model updating.In the model updating hybrid simulation,the physical substructure has a great influence on the test accuracy,and how to select the appropriate physical substructure for different structural systems is also a difficult problem.This thesis firstly takes the relevant components in the lateral force resistance system in the frame structure as the research object,proposes a Multi-substructure model updating hybrid simulation method,and builds two sets of test frameworks for online updating and offline updating respectively.This method increases the number of physical substructures in the model updating hybrid simulation,and focuses on the feasibility of online and offline methods when the number of substructures increases.Besides,by comparing the accuracy,this method selects a suitable test method to apply it in real experiments.Secondly,this thesis takes a reinforced concrete full-scale column quasi-static test as the background to carry out a research on the offline model updating hybrid test of real components.The research contents are as follows:(1)The basic principle of unscented Kalman filter(UKF)algorithm is expounded,and the parameters of Bouc-Wen model components are identified.The results show that UKF algorithm has high identification accuracy for nonlinear systems,and can be used as a parameter identification algorithm in model updating hybrid simulation.The UKF algorithm is used to carry out online identification under irregular loading paths and offline identification under regular loading paths for different nonlinear components.The parameter identification results show that the UKF algorithm has high accuracy under different loading paths,but its recognition efficiency will be affected by the loading path.The algorithm under the regular quasi-static loading path has higher recognition efficiency.(2)For Multi-substructure systems,two sets of test frameworks for online model updating and offline model updating are established respectively,and virtual hybrid tests of different structure systems are completed through Open Sees and Matlab.The research results show that the Multi-substructure model updating can improve the accuracy of the hybrid test,and the accuracy improved by the offline updating is relatively higher.Numerical simulation is making preparation for the real test,considering the test technology,test cost and test accuracy,for Multi-substructure systems,offline model updating is a better choice in the model update hybrid simulation method,which can be extended to real tests.(3)According to the quasi-static test of the full-scale RC column carried out by the research group,taking the full-scale RC column as the physical substructure,an offline model update hybrid test was carried out on a seven-story three-span frame structure.The results show that offline model updating can improve test accuracy when substructure is RC column with complex properties.According to the empirical formula of the Ibarra-Medina-Krawinkler(IMK)restoring force model,the full-scale column quasi-static test data is used to simulate the seismic response of a four-story three-span frame.The research results show that the offline model updating can realize the reuse of test data to a certain extent.The application range of the hybrid test is expanded,and the significance of the full-scale column test is improved.