(University of the Witwatersrand, Johannesburg, 2023-11) Saunders, Shawn Wayne Valintino; Elvin, Alex
The efficiencies of cross sections and configurations applied to vertical bracing are investigated by evaluating reference configurations (RCs), composed of cross braced circular hollow section (CHS) members, against comparative configurations (CCs), consisting of cross-braced Angle members, and single-CHS members. The metrics used to evaluate efficiencies were mass, raw materials costs, and fabrication and erection costs. CCs were found to be more efficient than RCs for most analysed cases, metric and configuration dependent. The following results were found:
i. Mass metric
a. Crossed-Angle more efficient in 79% of analysed cases.
b. Single CHS more efficient in 87% of analysed cases.
ii. Raw materials costs metric
a. Crossed-Angle more efficient in 92% of analysed cases
b. Single CHS more efficient in 88% of analysed cases
iii. Fabrication and erection costs metric
a. Crossed-Angle more efficient in 90.4% of analysed cases
b. Single CHS more efficient in 88.5% of analysed cases
Inversions of the efficiency parameter findings, with RCs more efficient than
CCs, were observed when:
i. RC CHS member slenderness ratios were less than 80-90.
ii. CC design loads were greater than 225 kN, 1200 kN and 1500 kN for
mass, raw materials and total cost efficiency metrics, respectively