Compressive strength of collar plate reinforced SHS T-joints: Effect of geometrical parameters and chord stress ratio

Abstract

The collar plate (CP) is applicable for the reinforcement of both new designed and in-service joints, yet the design approach for the reinforcement requires further investigation. The current paper investigates the effect of various geometrical parameters as well as chord stress ratios on the compressive capacity of the collar plate reinforced (CPR) square hollow section (SHS) T-joints. The finite element (FE) models of the CPR SHS T-joints are built and validated using experimental data. Extensive parametric studies are carried out to evaluate the influence of parameters such as the brace to chord width ratio, the width/length and thickness of the CP, as well as the chord stress ratio. The brace to chord width ratio and the CP thickness are identified as the key parameters, and three typical failure modes are observed. Finally, bearing mechanism of CPR T-joints is discussed and design equations are proposed based on the failure modes. The failure-mode-based equations agree well with both parametric data and orthogonal analysis results, which provides reference for the practicing engineers.

Seismic Performance of Rectangular Hollow Section X-Joints Subjected to In-Plane Bending Moment

“…In the effort to improve the strength of the RHS joints, many strengthening measures have received attention. For example, collar plate strengthening for the T-joints was studied by Chang et al [21], sidewall plate strengthening for the T-joints was studied by Gomes et al [22], and the seismic behavior of a prefabricated steel-braced frame structure with hinged joints was studied by Jia et al [23]. It was found that these strengthening measures could effectively increase the strength of the RHS joints.…”

Experimental and numerical assessment of CHS-RHS T-joints with chords subjected to axial tensile forces

“…Thus, other recent studies (Kim and Lee, 2020; Lima et al, 2018a; Nizer et al, 2016) have shown that, depending on the intensity of tension stresses in a chord, an increase in joint resistance could occur, what was never found in compression cases. For cases with compression stresses, the brace-to-chord ratio was identified as a critical parameter that influenced the joint strength of T-joints with reinforcements (Chang et al, 2020). Therefore, for the consideration of the effect of the stresses from axial forces and bending moments acting in the chord and affecting the joint resistance, adequate chord stress functions are fundamental for the proper joint design.…”