Design of direct-formed square and rectangular hollow section stub columns

Effects of galvanizing on residual stresses and stress concentrations in RHS X- and T-Connections

“…1), nearly the same steps are followed in all facilities. The immersion time for individual parts of a truss is strictly controlled (approximately five minutes for each connection) to produce the best coating quality [1][2][3][4][5][6][7][8][9][10]. For cold-formed hollow structural section (HSS), similar to the heat treatment (also at 450°C) per ASTM A1085 Supplement S1 [11], or the Class H finish per CSA G40.20/G40.21 [12], the galvanizing temperature has little effect on the material strength and ductility as a higher temperature is needed to produce metallurgical changes.…”

“…For cold-formed hollow structural section (HSS), similar to the heat treatment (also at 450°C) per ASTM A1085 Supplement S1 [11], or the Class H finish per CSA G40.20/G40.21 [12], the galvanizing temperature has little effect on the material strength and ductility as a higher temperature is needed to produce metallurgical changes. However, this process inevitably changes the residual stress magnitudes and distributions in cold-formed HSS members [1][2][3][4][5][6][7][8][9][10]. To facilitate the application of galvanized high-strength HSS in infrastructure projects, recent research [2,[6][7][8][9][10] showed that, for commonly specified crosssectional sizes, similar to the heat treatment per ASTM A1085 [11] and CSA G40.20/G40.21 [12], hot-dip galvanizing can improve member behaviours under axial compressive and flexural loads through effective partial residual stress relief.…”

“…However, this process inevitably changes the residual stress magnitudes and distributions in cold-formed HSS members [1][2][3][4][5][6][7][8][9][10]. To facilitate the application of galvanized high-strength HSS in infrastructure projects, recent research [2,[6][7][8][9][10] showed that, for commonly specified crosssectional sizes, similar to the heat treatment per ASTM A1085 [11] and CSA G40.20/G40.21 [12], hot-dip galvanizing can improve member behaviours under axial compressive and flexural loads through effective partial residual stress relief.…”

“…On the other hand, an excessively long immersion time will result in an excessively thick zinc coating. Such coating is not economic and can be brittle due to the overreaction between the zinc bath and the base steel [1][2][3][4][5][6][7][8][9][10]. For unbraced thin-walled steel sections, the thermal effect of the hot dipping process can sometimes cause warpage and distortion [1].…”

Compressive behaviors of modular steel shear-keyed grouped tubular columns

“…For example, Theofanous and Gardner [53] found that the EC3 effective width equation and Class 3 slenderness limit for stub and long stainless steel SHS columns are conservative. Kamran and Min [54] witnessed AISC360-16, CSA S16-19, and AISI S100-16 to be safe for SHS/RHS cold-formed stub columns. Liu et al [55] discovered that Class 1~4 slenderness limits in EC-3 and ANSI/ AISC 360-16 for Q355 and Q460 mild steel columns are non-conservative.…”