Sensitivity analysis of geometrical design parameters on the compressive strength of the vertical inner-plate reinforced square hollow section T-joints: A finite element study

Abstract

In present study, the normalized axial compressive strength (Qu) of the vertical inner-plate reinforced (VIPR) square hollow section (SHS) T-joints was systematically investigated under various geometrical design parameters of the joint, such as width ratio of the brace and the chord (β), thickness ratio of the vertical inner plate and chord flange (τip), ratio of the outstretch length of the vertical inner plate from the brace to the width of the chord (γip), height and width ratio of the brace (η1). First, a finite element (FE) model of the VIPR SHS T-joint was developed and validated by using experimental data. Then, a large scale of parametric studies was carried out to identify the critical geometrical design parameters that influence the Qu of the VIPR SHS T-joint. The results show that Qu increases with the increase of β, and the rate of increase becomes more obvious under a large β. In addition, under a relatively small β (i.e. β < 0.6), the yielding of the chord flange is mainly controlled by the vertical inner plate, whereas the yielding of the chord flange is controlled by the brace under a large β. It also demonstrates that the vertical inner plate can mitigate the risk of buckling failure of chord web, and Qu increases with the increase of γip. Furthermore, this study proposed an empirical equation which could potentially be used by the practicing engineers to evaluate the axial compressive strength of VIPR SHS T-joints under various geometrical design parameters.