Pseudo-dynamic Tests Of A New Type Sixstorey Fabricated Spatial Steel Frame

Steel frame with construction member resisting the lateral load is a new kind of aseismicity structure system, which is applied to fabricated steel structure residence systems. It has a broad prospect for application because of its better environmental protection, industrialized production, easy installation and maintenance. Based on the research — adjustable beam height fabricated joint and cross soft-core bucklingrestrained brace, the article combines pseudo-dynamic test and finite element analysis to study the aseismicity of new type fabricated steel frame composed of H steel beam and steel column systematically. The main research contents are as follows:1) Experimental study: Test system prototype of prefabricated steel framework system with 7 intensity is transformed to scale test model with the proportion of 1:4. According to the laboratory conditions, various indicators are adjusted to meet scale requires by setting the counter weight and shortening the cycle. Test procedures include steel frame and frame buckling-restrained support. Using two MTS actuators with three layers and six layers, pseudo-dynamic loading is conducted by loading system of displacement control. Analyzing response and phenomenon of structural system in different working condition of the ground motion, we verify whether deformation and strength meet code requirements beneath the effect of ground motion intensity. It obtains the contributions of destructional form and aseismicity of buckling-restrained support. Also, the basic mechanical properties and failure mode in each component and connected nodes are observed.2) Numerical analysis: ABAQUS is adopted to build the detailed model of two systems. Firstly, the results of finite element calculation are validated by testing results. Then, model system is observed in different stage of elasticity and plasticity by increasing input seismic load step by step. At same time, failure modes and non-loading layer data that hard to get in the test are supplied.The main results indicate: two models’ deformation both satisfied the request of standard under seismic load, and have good seismic behaviors and good energy-dissipating capacity; the adjustable beam height joint is in accordance with the request of the stronger joint with no damage but it deforms because of eccentric compression torsion in positive and negative bending moment; buckling-restrained brace is destroyed ahead of structure under strong earthquakes, which can alert and prevent energy dissipation. Variable cross-section of end socket in inner core twists off and it can be maintained by changing new support.