Study On Seismic Hybrid Test Method Based On Reduction Of Structural Modal Dynamic Freedom

Structural seismic hybrid test method is the most economical and reasonable research method to study the seismic performance of structures.To study the seismic performance of large and complex structures under earthquakes,improve the efficiency of structural dynamic analysis,and reasonably reduce the dynamic degrees of freedom of structures.The reduction synthesis method is proposed based on the reduction of substructure modal dynamic Degree of Freedom(DOF).And the reduction method is combined with structural seismic hybrid test.A reduction hybrid test system of dynamic DOF for high-rise frame structure is established,based on the dynamic characteristics of the high-rise frame structure.The main contents are as follows:(1)The research status of the seismic hybrid test method and modal synthesis method were reviewed,and the breakthrough directions of the two methods that need further research were summarized.The problems in the reduction of DOF of large complex structures was discussed and the solutions in combination with seismic mixing test was proposed in the paper.(2)The basic principles of modal synthesis method and the reduction method of DOF were outlined.According to the need for the reduction of DOF for high-rise and super highrise frame structures,a reduction synthesis method of DOF based on substructure modal was proposed.The DOF of the overall structure was separated by using dynamic-static DOF equivalent separation methods.The complexity of the static restoring force information of the structure was retained.And the dynamic DOF of the structure was reasonably reduced through the modal analysis of the substructure and the coherence of the quality for substructure.A simplified dynamic model was formed and the equations of motion for the model was solved.(3)Taking an ideal typical high-rise steel frame structure as the verification model.And the structural modal analysis was carried out by using ABAQUS software.The effectiveness of the synthesis method for the reduction of dynamic DOF proposed was researched based on substructure modal;the dynamic characteristics of the simplified dynamic model and verify the feasibility of the reduction method of DOF was verified by comparing with the overall structural modal analysis results(4)Combined with the comprehensive method of the reduction of dynamic DOF proposed in the paper,a concrete high-rise reinforced concrete frame structure was taken as the research object to establish a hybrid test system of the DOF reduction for high-rise frame structures.And the numerical simulation of the reduction of dynamic DOF hybrid test for the high-rise reinforced concrete frame structure was realized.At the same time,the finite element analysis model of the whole structure was established to analyze the dynamic characteristics of the whole structure and the response under the earthquake.Through a comprehensive comparison with the seismic response of the whole structure,the feasibility and effectiveness of the reduction of DOF hybrid test system for mixed high-rise reinforced concrete frame structure was verified.