The Study Of Pseudo-Dynamic Test Method Based On Openfresco Used In Nonlinear Substructure

With the civil engineering structures developing toward complex, large-scale direction, methods of structural tests especially seismic test method requirements have become increasingly high. Substructure pseudo-dynamic test method, also known as hybrid test method, the test method is a new seismic test method and it is also a hot topic of research at home and abroad.This article is in use of the software OpenFresco developed by the University of California, Berkeley American, research on application of the hybrid testing method of nonlinear substructures. At present the research on this topic is not common in the country, there are still many problems to be solved especially in the application for the test method of nonlinear test substructures. For example during the process of hybrid test, the selection of numerical integral algorithm can as much as possible to guarantee the test precision of nonlinear substructures; Setting what kind of test parameters to ensure the stability of the test system; How to simulate the experimental substructure boundary conditions to achieve the accurate analysis of the whole structure.According to these problems, this paper mainly completed the following aspeets of the work:(1) The test principle of hybrid testing method is discussed. Describes several numerical integration algorithm and chose proper numerical integration algorithm according to the test. The hybrid test system components are introduced and given some precautions for use.(2) Two kinds of three storey single span steel frame model with viscous damper are modeled and analyzed by finite element software SAP2000.(3) The steel frame of three storey and single span by hybrid simulation verify the feasibility and stability of hybrid test system.(4) The viscous damper is studied under quasi-static test to get test results of its seismic performance, providing accurate parameters for the next step of the hybrid test and analysis.(5) According to the different position of the viscous damper as experimental substructure, set up four test models of the three layer single span steel frame, respectively hybrid tests are carried out.(6) The pseudo static test and hybrid test results of viscous damper are compared and analyzed; Finite element numerical simulation results and results of hybrid test are compared and analyzed; The hybrid test results of dampers arranged in different layers are compared and analyzed. Finally, analyze the cause of errors, and propose the corresponding solution.