Boundary Coordination Technology And Application Of Structural Hybrid Test

The hybrid test method is a kind of structural test method commonly used in recent years.In a hybrid test,the computer and experimental equipment distributed in different places can be integrated to carry out structural experiments by dividing the overall structure into several computational substructures and numerical substructures.Most of the hybrid test research in the past focus on the development of test platform or the application of frame strcutures which has less degrees of freedom at the boundary of substructures,while research on the boundary conditions between substructures is rarely reported.Because of the adoption of substructure technique in hybrid test,the simulation accuracy of boundary conditions of each substructure has a great influence on the simulation of the seismic response of the whole structure.In this paper,boundary conditions of different kinds of structures are studied under hybrid test.The equivalent linearization method is frequently used in the analysis of energy dissipation structure.In this paper,the relationship between the deformation of steel dampers and the deformation of storey drift in the equivalent linearization analysis is studied,and the influence factors of deformation mode of steel damping structures are proposed.A simplified method of displacement reduction coefficient is proposed according to the structure deformation mode.Numerical simulation shows:(1)the accuracy of the proposed simplified method,(2)the deformation mode of the damping wall is related to the assumption of the boundary condition,and the accuracy of the boundary condition has important influence on the accuracy of the analysis of the energy dissipation structure.Boundary condition of frame structure in hybrid test is studied.A 'physical domain overlapping' method is proposed in this part,which means the tested substructure is extended into the numerical substructure and creates an overlapping domain.By pin assumption at the midpoint of the beam and column in the extended part,the problem of bending moment application of tested substructure is solved.The accuracy of the "physics domain overlapping" method is verified by the numerical comparative analysis with the whole model.By adopting the combination of open and closed loop control test control method,the hybrid test was conducted on a four-floor frame structure.And the result shows the accuracy of the proposed method,and proves that the proposed method has the ability of simulation of nonlinear structure.Boundary condition of the high-rise shear wall structure in hybrid test is studied and a 'numerical domain overlapping'method is proposed.By extending the numerical substructure component to the tested substructure,a 'numerical overlapping domain' is created,by which the application of the overturning angle at the bottom of the numerical substructure can be avoided and the stress concentration caused by the constraint conditions introduced in the boundary treatment of the numerical substructure boundary in the conventional simulation method is solved,thus improving the accuracy of the simulation.The vertical force application is subdivided into a constant part and a variable part,realized by prestressed reinforcement and loading jack,respectively.Open-loop control method is adopted on the application of tested substructure overturning moment.The accuracy of the 'numerical domain overlapping' method is verified by numerical comparative simulation of 'nondomain overlapping','domain overlapping' and the structure overall analysis.In the end,the 'domain overlapping' method is used on the hybrid test of a 120-meter-high shear wall structure,and the accuracy and validity of the proposed method are proved.Finally,the 'physical domain overlapping' method is adopted in the hybrid test of the frame structure with steel damper with slits.The results show the difference of the deformation of steel damper and the storey drift,which proves the influence on the accracy of the test of the steel damper wall boundary conditions.And it is further proved that the 'physical domain overlapping' method is effective for the frame structure.