Model Updating Method For Substructure Pesudo-dynamic Test

Substructure pseudo dynamic test is often used to evaluate the seismic response of structures. However, because of limited available test equipment, only a small number of components can be selected as the experimental substructure, and the rest of the structure is simulated as a numerical substructure. Therefore, there are two problems in the substructure pseudo dynamic test.(1) In the substructure pseudo dynamic test, only a few members are tested as the experimental substructure, how much increase in accuracy can be achieved by the substructure pseudo dynamic test?(2) How to improve the accuracy of substructure pseudo dynamic test under the condition that the number of test substructures is limited? When a complex structure system is subjected to strong earthquake excitation, the portion of numerical substructure is possible to enter strongly nonlinear state, which undoubtedly increases the difficulty of numerical simulation. When the hysteretic model of numerical substructure is not accurate, it will affect the accur acy of the substructure pseudo-dynamic test. In order to improve the accuracy of the substructure pseudo dynamic test, model updating method for substructure pseudo-dynamic test is introduced. In the process of substructure pseudo dynamic test, the test data of experimental substructure is used to modify the hysteretic model of numerical substructure which has the similar characteristics with experimental substructures.In this thesis, based on traditional substructure pseudo-dynamic test method, model updating method for substructure pseudo-dynamic test is realized by using finite element software Open SEES and Tcl programming language, in which the restoring force model parameters of experimental substructure is identify by using the least square method.Firstly, the basic theory of substructure pseudo-dynamic test method is described, including the basic principles of substructure pseudo-dynamic test, the dynamic equation of general structure for substructure pseudo dynamic test, and the coordination of boundary conditions between substructures. Secondly, the method of using least square method to identify the stiffness parameters of linear elastic restoring force model is introduced.Based on finite element software Open SEES, the theory of complex nonlinear dynamic analysis is described. Taking a shear model and a frame model with buckling-restrained brace as examples, the effect of substructure number on substructure pseudo-dynamic test results is investigated based on time-history analysis using Open SEES.A substructure pseudo dynamic test program with model updating technique is developed by using Open SEES. The composition of program modules, data exchange between modules, model parameter updating method of numerical substructure, and coordination of boundary conditions between substructures are introduced in detail.Using the program, a model updating experiment under the same loading path is carried out, which verifies the recognition ability of the least square method and the feasibility and validity of the program. Taking a single-bay two-story frame with diagonal bracing, the model updating substructure pseudo-dynamic test is carried out. The experimental results show that the proposed model updating method can effectively improve the accuracy of th e substructure pseudo-dynamic test, compared with the traditional test method.