Study On The Mechanical Properties Of Concrete Filled Double Skin Multibarrel Tube Column

Nowadays,new requirements are put forward to the mechanical properties of heavy-load columns in the continuous development of the volume of building structures with great improvement in engineering technologies.In recent years,people start to focusing on the study of compound concrete filled steel tubular column under the research of new concrete filled steel tube structures.Four types of the concrete filled double skin multibarrel tube columns(the external cylindrical internal circular,external internal circular,external internal square,external cylindrical internal square type)were proposed to improving mechanical properties of structural column under the length diameter ratio.With great advantages in deadweight,bending rigidity and seismic ductility,the aforementioned constructional elements make it possible to save materials and reduce the cost of components without using thick wall steel pipe while satisfying the force requirements.In this paper,finite element software ANSYS was used to simulate the axial force of the short-pillar axial compression,long-pillar axial compression and eccentric compression of hollow sandwich composite CFST.The main work was done as follows:(1)On the basis of previous study on the mechanical properties of CFST columns,the appropriate steel and concrete material constitutive relation and contact model were selected to establish the finite element simulation model of four section form concrete hollow sandwich composite steel pipe column with finite element software ANSYS.(2)Analyzing the short columns' bearing capability of four section form concrete hollow sandwich composite steel pipe column,work characteristic and failure form under axial compression mode,as well as variations and influencing factors of bearing capacity to provide a basis for fitting the bearing capacity formula of short columns by using the finite element software ANSYS.(3)Analyzing the long columns' bearing capability of four section form concrete hollow sandwich composite steel pipe column,work characteristic and failure form under axial compression mode,as well as variations and influencing factors of bearing capacity to provide a basis for fitting the bearing capacity formula of long columns by using the finite element software ANSYS.(4)Analyzing the mechanical behaviors of four section form concrete hollow sandwich composite steel pipe column under eccentric compression,work characteristic and failure form under axial compression mode,as well as variations and influencingfactors of bearing capacity to provide a basis for fitting the bearing capacity formula of eccentric columns by using the finite element software ANSYS.(5)Based on the unified strength theory,above-mentioned analysis results and research for calculation of the four section forms the concrete hollow sandwich compound steel pipe column bearing capacity,the writer utilized formulas of short and long column bearing capacity and eccentric compression bearing capacity calculation,and compared the theoretical research data and engineering design analysis.The obtained results are in great agreement.