Study On The Bidirectional Force Performance Of A New Type Of Stainless Steel Pipe Concrete Column

The new stainless steel tube concrete is a new type of combined structure developed under the background of today’s high-performance building structure.This new composite structure has the advantages of safety,durability,harmony and good workability of the composite ordinary steel tube concrete structure,while meeting the requirements of beauty,durability and corrosion resistance.In this paper,the seismic performance of the new stainless steel tube concrete column is studied.The mechanical performance and working mechanism of the new stainless steel tube concrete column under oblique low-cycle reciprocating load and two-way eccentricity are studied from both experimental and theoretical aspects.The work mainly includes the following aspects:(1)This paper has completed the experimental study of 8 square specimens and 9rectangular specimens under oblique low-cycle reciprocating loads.The parameters investigated in the experiment are: axial compression ratio,loading angle,inner and outer pipe size ratio,etc.The influence of various parameters on the new stainless steel pipe concrete column is studied,including the final failure form,load-displacement hysteresis curve,skeleton line,stiffness Degradation,ductility,energy dissipation capacity,strain,bending moment-curvature relationship,etc.The experimental study of 10 square specimens and 12 rectangular specimens under bidirectional eccentric compression has been completed.The parameters examined in the experiment are eccentricity angle,eccentricity distance,slenderness ratio,etc.,and the influence of various parameters on the new stainless steel pipe concrete column is studied,including load-displacement curve,component deflection and deformation,steel pipe strain development,etc..(2)In this paper,the finite element software ABAQUS is used to establish the finite element model of the new stainless steel pipe concrete column.The finite element calculation results are in good agreement with the test results,which verifies the applicability of the finite element model.(3)This paper uses the verified finite element model to analyze the performance of the new stainless steel pipe concrete column under oblique force and two-way eccentric compression.The working mechanism includes the outer stainless steel pipe,sandwich concrete,inner steel pipe,and core concrete.Stress state.(4)This paper uses the finite element model ABAQUS to analyze the parameters of the new stainless steel pipe concrete column.The changing parameters are: the yield strength of the outer stainless steel material,the yield strength of the inner ordinary steel pipe,the cylindrical compressive strength of the sandwich concrete,the cylindrical compressive strength of the core concrete,etc.,and on this basis,the new type of oblique force is applied.A simplified calculation method is proposed for the stainless steel tube concrete column,and the test results of the new type of stainless steel tube concrete column subjected to bidirectional eccentric force are compared and analyzed with the calculation methods in the American AISC code,the European EC4 code and the Fujian Provincial Technical Code for Concrete Filled Steel Tube Structures DBJ.