The Mechanical Properties And Parametric Analysis Of Stiffening Rib-concrete Filled Steel Tubular Short Column

With the increasing height and span of the building structure,the section size of the column becomes larger and larger which not only occupy much more space but also result in'fat columns',which is not beneficial to anti-seismic.To solve this problem,a new type of composite column(the Stiffening Rib-Concrete Filled steel tubular Column,abbreviated to SRCFC)is designed based on the research results of the composite column involving the concrete filled steel tubular,the steel reinforced concrete and the steel tubular column filled with the steel-reinforced concrete.As a result of embedding steel in concrete,the core concrete gets a lager constrain force.The new type of composite column possesses advantages of higher bearing capacity,lager flexibility and higher utilization rate of building space.Mechanical performance,working mechanism,calculation methods for bearing capacity regarding this new type composite column are studied in this paper.The major researches include several parts:(1)Mechanical behaviors of the SRCFC under compression load is simulated using the ABAQUS finite element software,and compare with the results in the open literatures.Coincide results verify the correctness of the calculation model.The numerical results also show that bearing capacity of SRCFC is 10%?30%higher than ordinary concrete filled steel tube column.Besides,the stiffener,the constraint model of steel tube and concrete,the contact pressure and the bond-slip law are discussed,and the working mechanism of SRCFC is cleared.(2)Considering the effective constraint area of steel tube and stiffening rib on concrete,based on the limit equilibrium theory,the computational formula of the ultimate bearing capacity of SRCFC is deduced.Comparing with those relevant formulas in the literature,it verifies the practicality and reliability of the proposed formula in this paper.(3)This paper carries out parameter analysis of the SRCFC from the width-to-thickness ratio of stiffening rib,the diameter thickness ratio of steel pipe,the strength of materials,the strength of contact friction and other aspects,obtains the influence law of mechanical properties and sums up the sensitive factor.It analyses five different cross-section forms of stiffening rib on the influence law of bearing capacity,and proposes the economical stiffener section forms.