Simulating the hot dip galvanizing process of high mast illumination poles. Part II: Effects of geometrical properties and galvanizing practices

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.…”

“…Residual stress on welded joint surface: 250-400 MPa (1) RHS members (indirect-and direct-formed) [15] Nominal (2) RHS members (indirect-and direct-formed) [7] Nominal: 350 MPa Measured: 367-483 MPa (3) Cold forming Average of bending residual stresses over entire cross-section: 62%-80% of measured yield strengths (4) Galvanized RHS members (indirect-and direct-formed) [7] Nominal: 350 MPa Measured: 367-483 MPa (3) Cold forming and galvanizing Average of bending residual stresses over entire cross-section: 33%-50% of measured yield strengths (4) High-strength RHS members (direct-formed) [7] Nominal: 690 MPa Measured: 638-730 MPa (3) Cold forming Average of bending residual stresses over entire cross-section: 49%-69% of measured yield strengths (4) Galvanized high-strength RHS members (direct-formed) [7] Nominal: 690 MPa Measured: 638-730 MPa (3) Cold forming and galvanizing Average of bending residual stresses over entire cross-section: 24%-37% of measured yield strengths (4) (1) The residual stresses are measured on connection surface adjacent to weld seam, using the hole-drilling, X-ray diffraction or neutron diffraction approach. (2) The residual stresses are measured using the hole-drilling and sectioning approaches.…”

“…When galvanizing steel trusses of commonly specified sizes (Fig. 1), nearly the same steps are followed in all facilities [1][2][3][4][5]. The dipping and withdrawing rates are carefully controlled to ensure sufficient reactivity and in turn good coverage and quality of coating.…”

Designing a Low-Cost System to Monitor the Structural Behavior of Street Lighting Poles in Smart Cities

“…It is summarily hidden underground or concealed by protective sheaths and a concrete base. For this reason, the prediction of possible structural damage becomes extensively complex [ 20 ]. However, a structural collapse can also occur due to extreme causes, such as road accidents [ 21 ] and adverse weather conditions [ 22 ].…”