In this modern and developing era, demand for new buildings and construction ideas are unavoidable. Consequently, scarcity of ever depleting resources has propelled developers to begin new building techniques and construction method. Therefore, a new steel structure, which is widely known as cold-formed steel, is introduced to replace current wall building materials such as concrete, timber, bricks as well as masonry blocks.
Apart from wall, cold-formed steel structures are also widely used in forms of roof decks,floor decks, bridge forms and so forth but to name a few. As for load bearing structural components, cold-formed steel section has been widely applied ranging from automobile industry to space industries. In comparison with hot-rolled steel, cold-formed steel has a number of advantages due to its lightweight material, high stiffness, ease of fabrication, ease of installation and no framework is needed. Besides that, cold-formed steel is widely used in thin-walled structure design because it contains thin elements with large width-to-thickness ratio.
Cold-formed steel is slowly replacing timber due to its rot-proof, termite-proof, fire-resistant and recyclable. At varying temperatures, cold-formed steel will not shrink and creep when it is in ambient temperature. Cold-formed steel may also reduce the wastage from construction since they can be recycled or reused.
Despite the possession of economic advantages, cold-formed steel produces mode of failure and deformation which do not usually happen in normal structural steel design. Apart from that, cold-formed steel can buckle locally at a stress level which is much lower than the yield stress of steel which it is subjected to bending, compression or shear. Subsequently, if the cold-formed steel is provided with web or flange stiffeners, their performance will improve in terms of strength/weight and stiffness/weight ratios.
In this project, we are required to optimise the cold-formed ‘C’ sections by selecting the one which have the highest axial capacity with a fixed cross-sectional area, which is 94.48mm2. The aim of optimisation on cold-formed steel is to maintain the cost of cold-formed steel as it planned to become an alternative for timber.