Effect Of Geometrical Parameter On Static Behavior Of Gapped Shs KK-Type Connections

Among the directly welded SHS (square hollow section) joints, gapped KK-type SHS joints are very popular structural types,which consist of two K-type at an angle.Since KK-type SHS joints'excellent integrative performance makes they were widely used in engineering practice, but the current code does not cover KK-Joints formula. To solve this problem, this paper considering geometric nonlinearity and material nonlinearity, modeled using ANSYS finite element program to analyze the influential parameters of KK-type joints, and points out the law of influence. The results showed that:β,γhave significantly influence on the KK-type joints'stiffness and strengths , g,θ,n,e have considerable influence, andτ,ψhave a little impact. The experimental data were compared with finite element results to verify the accuracy and precision of the finite element method, the results matched very well.The existing research has focused on spatial angle of 90°and longitudinal off-center web members. In this paper the space angle of 45°, 60°, 90°and transverse off-center were analyzed. The compression members have lower strengths than the tension members, so changing the compression members to study the mechanical properties of the KK-type joints on the premise of does not changing the tension members, the results showed that increasing tension members can effectively improve the overall performance of KK-type joints.In foreign design code the KK-type joints can be designed as K-type joints multiplied by the coefficient of spatial effects, in this paper the influence coefficient was verified. Combination of various parameters on the design of almost all cases, not only come to the ultimate strength of the KK-type joints, but also tracking joints of the load - displacement of the entire process .Although in some cases, the simulation results is lower than the proposed design formula, but the difference is within the allowable range. So the coefficient of spatial factor defined as 0.9 is reasonable. This paper also put forward proposals and the thing to consider when designed, and also pointed out the Direction to be further studied.