Study On Seismic Performance Of Hybrid Fiber Cement-based Composite Material Concrete-filled Steel Tube Composite Colume

Hybrid fiber cement-based composite material is a new type of cement-based composite material that has the advantages of good ductility,good impermeability,high tensile strength,and strong energy consumption.It can be used in engineering structures to enhance the seismic performance of the structure.Improve the durability and ductility of the structure.In order to overcome the shortcomings of concrete-filled steel tube and save the amount of steel,this paper intends to use hybrid fiber cement-based composite material to replace the reinforced concrete wrapper in the concrete-filled steel tube composite column to make hybrid fiber cement-based composite material-tube concrete composite column(HF-STC composite Column),in order to improve the seismic performance,the specific work is as follows.1)Based on the basic principles of the structural design of concrete-filled steel tube and concrete-filled steel tube composite columns,reasonable assumptions and simplifications are put forward,and the calculation methods of HF-STC column axial compression bearing capacity and eccentric compression bearing capacity of the HF-STC column are analyzed and deduced.And it defines the size eccentricity limit that is different from ordinary reinforced concrete.The derivation steps are detailed and rigorous and have a certain theoretical reference value,which provides a theoretical basis for the comprehensive mechanical analysis of the HF-STC composite column.2)Designed and fabricated 6 HF-STC composite column specimens,conducted low-cycle reverse loading tests and studied the hysteresis curve,skeleton curve,ductility,ductility,and ductility of the steel pipe thickness and axial compression ratio of the composite column.Earthquake resistance performance indicators such as energy dissipation capacity,stiffness degradation and failure form.The test results show that when the thickness of the steel pipe is 4mm and the axial compression ratio is 0.2,the HF-STC composite column has a relatively full hysteresis curve and skeleton curve,good ductility,excellent energy consumption and good failure modes.The disadvantage is that the horizontal bearing capacity is low,so the combined cross-section form is suitable as a non-load-bearing energy-consuming component,not as a load-bearing component.3)Using the finite element simulation software ABAQUS,using reasonable contact and boundary conditions,selecting a suitable constitutive model,simulating the low-cycle repeated test of the HF-STC composite column,and carrying out its failure form and hysteresis curve with the actual test Contrast.The comparison results show that the horizontal bearing capacity,ultimate displacement and failure form of the specimen are in good agreement with the test results,which proves the accuracy of the model established in this paper.