Size optimization of single edge folds for cold-formed structural members

Abstract

Parametric optimization problem for single edge fold size in cold-formed structural members subjected to central compression has been considered by the paper. Determination the load-bearing capacity of the cold-formed structural members has been performed using the geometrical properties calculated based on the constructed “effective” (reduced) cross-sections taking into account local buckling effects in the section as well as distortional buckling effects.
 Single edge fold size in cold-formed C-profile has been considered as design variable. Linear convolution of criteria, namely minimization criterion of design area of stiffener cross-section and maximization criterion effective area of stiffener cross-section which defines it reduced load-bearing capacity due to flexural buckling has been used as optimization criterion. The parametric optimization problem has been solved using the method of objective function gradient projection onto the active constraints surface with simultaneous correction of the constraints violations. In order to realize the formulated optimization problem, software OptCAD intended to solve parametric optimization problems for steel structural systems has been used.
 Optimization results of the single edge folds for the cold-formed С-profiles manufactured by «Blachy Pruszyński» company, «BF FACTORY» company as well as «STEELCO» company have been presented by the paper. The results of the performed investigation can be used as recommendations for companies-manufacturers of the cold-formed profiles, as well as a guide for creation the national assortment base of the effective cold-formed profiles promoting wider implementation of cold-formed steel structures in building practice.

Про Доцільність Та Формулювання Задач Пошуку Оптимальних Проєктних Рішень Стержневих Конструкцій Із Холодногнутих Профілів

“…У праці [8] розглядалася задача параметричної оптимізації розмірів поперечного перерізу С-подібного холодногнутого профілю, що працює в умовах центрального стиску. За критерій оптимальності брався критерій максимізації несучої здатності профілю на втрату загальної стійкості за центрального стиску, представлений у формі лінійної розгортки несучих здатностей, що враховують згинальне, крутильне та згинально-крутильне випинання стержневого елемента, визначені відповідно до нормативних вимог.…”

Optimization of cross-section dimensions of structural members made of cold-formed profiles using compromise search

“…The use of cold-formed thin-walled profiles was previously limited to cases where reducing the weight of the structure was a top priority, as, for example, in the aviation or automotive industry. Nevertheless, due to the development of manufacturing technology, corrosion protection, product availability, as well as an understanding of the design behavior and improvement of technical standards for the analysis of thin-walled rod elements, the use of coldformed structural members is gradually expanding [1].…”

Cross-Section Size Optimization of Cold-Formed Steel Lipped Channel Structural Members Subjected to Axial Compression

“…Previously, the use of cold-formed thin-walled profiles was limited to cases where reducing the weight of the structure was a priority, such as in the aviation or automotive industries. However, due to the development of production technology, corrosion protection, product availability as well as implementation of the design code the use of thin-walled structural elements, including cold-formed profiles is gradually expanding [1].…”

“…There are specific fields of application where their efficiency is the highest. However, the widespread application of the structures made from thin-walled cold-formed profiles of the domestic production is delayed due to the lack of domestic experience in economic and reliable design of such structures [1].…”

“…Particular attention has been paid to the optimal folding of the CFS structural members. In the paper [1] a parametric optimization problem for single edge fold size in CFS structural members subjected to axial compression has been considered. The purpose function and constraints of the mathematical model has been formulated as continuously differentiable functions, then the parametric optimization problems has been successfully solved using the gradient projection non-linear methods [18].…”