The process of determining the most effective design solution from the point of view of metal consumption for the dome structure of the designed exhibition complex in Rostov-on-Don with a plan diameter of 100 m is considered. Three different dome design options are analyzed. Calculation models were created in the Lira-SAPR software package and calculations of various coating options were performed. The obtained results were compared in terms of rigidity and conclusions were drawn about the possibility and feasibility of using each of the considered design solutions. The most efficient design option in terms of metal consumption was selected.

Keywords: metal structures, dome, metal consumption, material consumption

The process of optimizing the applied sections in steel frames with elements of variable stiffness, formed from rolled I-beams by their diagonal dissolution and subsequent welding, is considered. A table with groups of I-beams according to GOST R 57837-2017 is proposed, which are advisable to be used together to form a monosymmetrical I-beam of variable height. An algorithm for finding the optimal section is proposed, taking into account the discreteness of the assortment. The calculation of a typical building structure code 828KM according to the proposed algorithm is carried out and a comparative analysis of the applied sections with the found optimized sections is presented. The possibility of obtaining a more economical supporting structure, both in terms of metal consumption and in terms of the cost of rolled products, is noted.

Keywords: variable section, variable stiffness, diagonal opening, I-beam, steel frame

The process of finding the calculated lengths of the elements of a cross lattice using the displacement method in the case when both bars are not interrupted and when one of the bars is interrupted and overlapped by a gusset is considered. New formulas of the displacement method are proposed for finding the support reactions of an element having a spring fixation at one of the ends. A formula is proposed that allows you to determine the spring stiffness, with the help of which the operation of the connecting strip is simulated. A comparison is made of two calculation options: using the usual formulas of the displacement method and using the proposed new formulas. The calculation showed good convergence of the results with a significant simplification of the calculation process in the second case. A comparison of the calculated lengths obtained with the instructions of the current sets of rules is given. The possibility of adopting a more economical section when determining the calculated length by means of the displacement method is noted.

Keywords: estimated length, cross lattice, stability, critical force, truss