Yurchenko V. Development of steel frames structural form made from cold-formed profiles based on the solution of an optimization problem

The thesis is devoted to development of searching methodology for optimum design decisions of cold-formed steel frames and trusses, which covers mathematical model of optimization problem of the structures under consideration as well as methods and searching algorithms for optimum design decisions oriented on software implementation in computer-aided systems. Numerical researches devoted to estimation of warping deformations of thin-walled bar cross-sections adjacent to the structural joint and redistribution of warping and bi-moments in thin-walled bar structures has been performed. Shear stresses searching problem for an arbitrary cross-section of a thin-walled bar has been considered. Detail numerical algorithm for this problem has been elaborated and corresponded software implementation has been performed. Modification of the standard genetic algorithm has been proposed. New effective searching algorithm for optimum structural form of cold-formed steel frames and trusses has been constructed with optimization of geometrical scheme parameters and cross-section sizes of structural members taking into account post-buckling behaviour, constraints of functional volume as well as structural requirements. New effective structures have been developed as well as new shaping regularities for optimum structural design decisions of cold-formed steel frames and trusses have been obtained in scope of proposed searching methodology.