Optimum Design of Cold‐formed Steel Beams: Particle Swarm Optimisation and Numerical Analysis

Abstract

Cold-formed steel (CFS) members, when subjected to optimisation, can significantly increase their ultimate load carrying capacity leading to a more economical and efficient structural system. This paper presents the details of an investigation on optimisation of CFS beams subjected to bending capacity and an investigation of shear and web crippling capacities of optimised sections. The optimisation was aimed to meet construction constraints reported in Eurocode 3 (EC3). In this research, 4 different CFS sections were considered including the introduction of 2 novel sections (Super Sigma and Smart Beam) which has closer shear center to the web and less susceptible to web buckling. The bending capacity of the available sections were obtained based on the effective width method reported in EC3, while the optimisation procedure was performed using particle swarm optimisation (PSO). The capacities of the optimised CFS beams were also obtained using the nonlinear finite element (FE) analysis and the FE results were compared with EC3. The FE results showed that the Smart beam and Super Sigma claim dual advantage of increase in section moment capacity and restrain against torsional effect than the conventional CFS channel sections with the same amount of material. These optimised cold formed steel beams can be employed in light gauge steel building constructions.

A Critical Review on Optimization of Cold-Formed Steel Members for Better Structural and Thermal Performances

“…A variety of optimization techniques have been used in the earlier research to optimize CFS members, such as graph theory and ant colony optimization [114], Genetic Algorithms (GA) [20,50,98,113,[117][118][119][120][121][122][123][124], Particle Swarm Optimization (PSO) [21,91,111,[125][126][127][128][129][130], Direct Multi Search Optimization (DMS) [115], the Big Bang-Big Crunch algorithm (BB-BC) [131], self-shape optimization method [132], parameter-free method [133], Neutral Dynamic model [23,134,135], Simulated Annealing (SA) [112,113,124,136], the Gradient Descent Optimization (GDO) [113,122], the Trust-Region Method (TRM) [116], and Whale Optimization Algorithm (WOA) [37].…”

“…These optimization studies can also be split into two groups: (i) optimization without any constraints on the overall cross-sectional shape (unconstrained shape optimization) [113][114][115]121,123,132,137]; and (ii) optimization of the dimensions of a predefined cross-sectional shape (constrained shape optimization) [20,21,50,91,98,112,[116][117][118][119][120]122,[124][125][126][127][128][129][130][131]134,136,[138][139][140].The latter one is more practical and easier to manufacture. More recently, nonlinear Finite Element (FE) models have been widely applied in assessing the accuracy of optimization results [21,119,123,[125][126][127][128]130,131].…”

Development of affordable steel-framed modular buildings for emergency situations (Covid-19)

“…In parallel to modular research, the light gauge steel area is also subjected to advancements developing innovative structural member profiles to enhance the structural efficiency. Optimisation studies [19] , [20] , [21] , [22] , [23] , [24] have resulted in innovative Cold-Formed Steel (CFS) beam and column profiles with intermediate web and flange stiffeners. The objective of these optimisation studies was to maximise the structural capacity of CFS structural members for a given amount of material.…”

Optimal design of cold-formed steel lipped channel beams: Combined bending, shear, and web crippling

“…For example, Ye et al [13,14] optimised the lipped channel beams with intermediate web stiffeners and return lips, and introduced a novel folded-flange section. Gatheeshgar et al [15][16][17] performed optimisation studies of CFS sections and introduced optimised super-sigma sections which can bear approximately 65% higher bending capacity compared to the conventional lipped channel beam with the same amount of material.…”

“…Fig. 2 Optimised CFS beam sections for bending maintaining the same amount of material [13][14][15][16].…”