Application of different welding cost calculations for a stiffened column optimisation

Abstract

The cost minimisation of a cantilever stub column with a square box cross‐section and orthogonally stiffened side plates is formulated and solved. The constraints relate to the overall and stiffener torsional buckling of side plates and to the horizontal displacement of the column top due to a horizontal force. Halved rolled universal beam I‐section stiffeners are used in both directions. The cost function includes the costs of materials, assembly, welding, and painting. The variables are the thickness and width of the side plates, as well as the dimensions and numbers of stiffeners in both directions. The optimisation is performed using the particle swarm algorithm. A non‐linear finite element simulation is made to validate the results. Comparisons have been made using different welding techniques, including FCAW (flux‐cored arc welding), GMAW CO2 (gas metal arc welding with CO2), and SMAW (shielded metal arc welding).