Research On Bending Capacity Of L-Shaped Column Composed Of Concrete-filled Steel Tubes Connected By Steel Linking Plates

The land resources are scarce and the population is numerous as well as rising land prices in our country.With the continuous progress of society,people's demand for housing is also increasing,the problem of exposed beam and exposed column are no longer accepted by the public.As a new structure of residential structure,special-shaped columns have been widely recognized by people in recent years.The special-shaped column composed of concrete-filled steel tubes(SCFST)have been developed gradually from the original concrete special-shaped column.Experimental and numerical investigation of one LCFST column under axial loading is conducted which based on the previous studies.It is found that the actual centroid position of LCFST agrees with the theoretical calculation position,the relative position of loading location and centroid has a great influence on the failure mode.The single limb columns can coordinate deformation,and show good integrity and bearing capacity under axial loading.Experimental and numerical investigation of two LCFST columns under positive-eccentric loads around the weak axis are conducted.It is found that with the increase of the positive eccentricity,the overall bearing capacity and stiffness of the specimen decrease continuously,and the decreasing range gradually decreases.The ductility of the specimen increases gradually and the overall deflection increases.On the basis of verifying the accuracy of the finite element model,the N-M correlation curve of LCFST under eccentrically loads is given.Experimental and numerical investigation of two LCFST columns under negative-eccentric loads around the weak axis are conducted.It is found that all the performance changes of specimens is similar to that of specimens under positive-eccentric loads,however,the overall instability direction of the them is opposite,and the bearing capacity and deflection of the former are greater than those of the latter when the eccentricity is the same,and the weld is disadvantageous to the bending performance.Studies on modelling two LCFST columns under eccentric loading considering the effects of eccentricities with simplified finite element model were conducted.Parametric analyses were further carried out using the simplified models above,the influence of concrete strength,steel strength,thickness of connecting plate and eccentricity on the bending performance of LCFST is given.