Bearing Capacity Analysis Of Multiplanar KX-, KT-joints Made Of Square Hollow Sections And Practical Design Formula

As structural component, square hollow steel sections have favorable properties for resisting compression, bending and torsion. The structures made of square hollow steel sections by using the directly welded joints are fabricated easily and economically, which can be found in many applications all over the world. But now, the research on the multiplanar KX-, KT-joints that have been used in many projects is little, which brings some inconvenience to the extension and application for this type of joints.The key problem in the designing of this structure is the ultimate bearing capacity of the directly welded joints(also called simple joints). Because the stress distribution around the joint is complicated, it is restricted using analytical method to calculate its bearing capacity, and the commonly research approaches to this joint are experimental investigation and finite element modeling. In this paper, the finite element modeling method is used to do some plasto elasticity lager defection analysis for the multiplanar KX-, KT-joints. First, the bearing capacity of uniplanar K-, T-, and X-joints is analyzed. And then the multiplanar KX-, KT-joints is analyzed, the analysis results of which is contrasted with the former, so as to consider the effect on bearing capacity owing to the mutual effect of web member and branch member. At last, the suggested design formula of the bearing capacity for these two types of joint is presented.