Weld size and resistance in rectangular hollow section T-joints.

When chord face failure occurs, one of the factors, which influence the resistance of the square hollow sections joint is the brace-to-chord width ratio of the joint. This includes the size of the weld connecting the two members. The influence of weld type and weld size on the behaviour of rectangular and square hollow section joints was studied at the Czech Technical University in Prague. This paper describes an experimental and numerical investigation of square hollow section joints. The welded T-joints were loaded by axial compression. Three different types of welds were investigated - butt welds, fillet welds and a combination of these types. Experimental results for the T-joint together with material characteristics are provided. The paper presents a validation of the numerical model to experimental data. The research-oriented model with shell elements, prepared in RFEM finite element software, represents well the behaviour of square and rectangular hollow section joints. A parametric study with a broader range of sections was performed using the design-oriented shell elements model. Based on the results of the experimental and numerical investigations a modification of the analytical equations used in current prEN1993-1-8:2021 is proposed.