Experimental Research On Seismic Behavior Of Lightweight Aggregate Concrete Filled Rectangular Steel Tube Frame

Two lightweight aggregate concrete filled square steel tube column-rectangular steel tube beam frame test specimens and two lightweight aggregate concrete filled square steel tube column-steel beam frame test specimens were experimentally studied under constant axial load and cyclically lateral load. The steel ratio of column section and the form of beam section are considered as experimental parameters. And the seismic behavior such as displacement hysteretic curves, deformation ductility, energy dissipation, strength deterioration and stiffness degradation are researched. The examination results show that the lateral load versus lateral displacement hysteretic curves of the frames are plump shuttle shape, this indicates the frames have excellent seismic behavior; The deformation ductility coefficients are between 3.00 and 3.74, the energy dissipation coefficients are between 1.438 and 2.324, these explain the frames have excellent ability of deformation ductility and energy dissipation; The capacity, ductility and energy dissipation have obvious exaltation with the increase of steel ratio of column section; The frames which adopt steel beam have stable later capacity and excellent deformability ability under the same steel ratio of column section.Based on the experimental testing, the nonlinear finite element analysis using ABAQUS for lightweight aggregate concrete filled rectangular steel tube frame is carried out. The result shows that the theoretical analysis coincides the experimental testing better. Then, the factors which affect the P-Δcurve of lightweight aggregate concrete filled rectangular steel tube frame such as the steel ratio of column section, steel strength, concrete strength and axial load level of column were analyzed, and the laws which each factor affects were obtained. The study results can provide some foundation for the seismic behavior design of lightweight aggregate concrete filled rectangular steel tube frame.In sum, the research results show that the working capability of lightweight aggregate concrete filled rectangular steel tube frame can meet the requirements of seismic behavior, and this kind of frame has broad prospect for application.