Nonlinear FEM Analysis Of Multi-Planar XK-Type Joints Of Steel Tubular Members

In the paper, nonlinear finite element method (FEM) analysis of multi-planar joints of steel tubular members has been realized by ansys software. It traces the whole process of stress-strain of total loading stages, and the ultimate bearing capacity of the joints is gained. The paper has proved the correction of the methods & results of calculating by comparing the curved line of the loading-displacement of CHS with that gained in experiments. An inelastic and nonlinear finite element analysis of XK-type CHS joints has been completed. Then it makes the nonlinear FEM analysis of the multi-planar XK-type joints of steel tubular members, calculates the ultimate bearing capacity of various geometric parameters joints and does some research on the bearing capacity and plasticity areas. By comparing the results of finite element with domestic code, the paper also provides suggestions for further revising of the code. In order to provide the ultimate bearing capacity with a higher engineering precision, a lot of factors including grid dimension , boundary conditions and material properties are taken into consideration in the nonlinear finite element analysis. Based on a series of numerical analysis of steel tubular XK-type joints of various geometric parameters, the effect of the various geometric parameters on ultimate bearing capacity has been investigated. The regulations that the ultimate strength varies with geometric parameters and the destroying models of joints are obtained. The effect of stress of the chord on the ultimate strength is also investigated. Some constructive suggestions to the engineering design are put forward for reference in design and code revision.