Capacity of unstiffened multi-planar tubular KK-gap joints under anti-symmetric loading

Abstract

This research presents a mathematical formula for calculating the capacity of anti-symmetric loaded multi-planar KK gap joints. The study was conducted using a well-calibrated and validated finite-element model, with 172 records generated for the parametric study using different geometries, member sections, and material properties. The results of the parametric study were analyzed using the GRG solving technique to develop a final predictive model. The developed model can predict actual joint capacity as a 3D joint, rather than approximating it as a 2D joint as in previous literature. It consists of two equations based on the ratio of the gap (gt/gl) with a transition point of (gt/gl) ≈ 0.9, which distinguishes between two different modes of load-transfer mechanisms: membrane action and direct shear action. The formula results were compared with experimental test results and showed an average accuracy of 91.2%.

Keywords

• Tubular KK- gap joints
• Multi-planar connection
• Anti-symmetric loading
• Unstiffened
• GRG