Introduction. Welded I-beams with a transversely corrugated wall when loaded in the wall plane are calculated for overall stability in accordance with paragraph 20.6.3.11 of СП 294.1325800.2017, change 2 from 06/15/2021. Here, a separate centrally compressed girder belt is calculated for overall longitudinal stability from the plane of the beam wall as an element pivotally supported at the ends. This does not take into account the joint work of the compressed belt with the wall, supporting ribs, stretched belt.The authors set a goal to show by calculation using the examples of six beams that if, in comparison with the calculation according to СП 294.1325800.2017, the joint work of the compressed belt with the wall, support ribs, stretched belt is taken into account, then the calculated critical load of the total loss of stability of the corrugator will be greater. And this increase is the more significant, the lower the height of the corrugator. At the same time, the authors limited themselves to considering beams with a ratio of sizes and critical loads that ensure the operation of steel in the elastic stage with loss of overall stability.Materials and methods. The general stability of split beams with a transversely corrugated wall was studied by calculation in three ways: according to СП 294.1325800.2017, in the LIRA-CAD PC by modelling beams with shell elements, including belts, walls and support ribs, and according to CП 16.13330.2017, considering a welded I-beam with a flat wall equivalent to the criterion of general stability.The results of the study. The data of calculation of critical loads of the first form of loss of general stability of six split beams of the Zeman range with height are given 333, 500, 750, 1000, 1250, 1500 with a span of 6.0 m in three proposed ways with loading of the upper belt with a uniformly distributed load in the wall plane without loosening the compressed belt in the span and loosening the support sections from the wall plane and from rotation relative to the axis of the beams.Discussion and conclusions. For beams with a wall height of 333 mm, taking into account the joint work of the compressed belt with the wall, stretched belt, support ribs showed an increase in critical load in comparison with the calculation according to СП 294.1325800.2017 by 24%. With an increase in the height of the beams to 900-1000 mm, the difference in the values of critical loads calculated taking into account the joint work of the beam elements and according to СП 294.1325800.2017 non-linearly decreases to 3%. And for corrugated rollers with a height of 1000-1500 mm, this difference is less than 3%, which shows that it is possible to perform calculations of beams with a transversely corrugated wall of the Zeman range with heights of 1000-1500 mm for overall stability with sufficient accuracy for engineering calculations according to СП 294.1325800.2017.

The paper considers verification of calculation of split I-beams with two symmetry axes on the general Eulerian stability at transverse bending in the plane of maximum stiffness in the software package (PC) LIRA-SAD. Calculations for various loads are given. Numerical calculation results in PC LIRA-SAP are compared with calculation by analytical formulas of S.P. Timoshenko and V.Z. Vlasov. Conclusions about calculation accuracy in PC LIRA-SAD in comparison with analytical formulas analysis are made.

An engineering design procedure for calculating bending with torsion in corrugated beams, including finding the critical load of general stability, implemented in the commonly used MS Excel spreadsheet and verified in the LIRA-SAPR software package, has been proposed. The method makes it possible to take into account the beams section variability and corrugation parameters, to estimate the loading eccentricity effect, availability of supporting ribs and reinforcements of the compressed chord from the bending plane. Calculation results of particular design solutions for corrugated beams with definition of critical loads at transverse bending are given. Results of test calculation of a bent channel beam with calculation of stress-strain state parameters and its verification with the LIRA-SAP software package are given.

In this paper, the calculation of cut corrugated beams loaded with uniformly distributed load in the plane of the wall, with a wall height of 333 and 500 mm (54 sizes), chord width from 160 to 400 mm and chord thickness from 6 to 30 mm for general stability in accordance with Building Codes (BC) 294.1325800.2017 is made. A geometric criterion has been defined which defines the boundaries of the load-carrying capacity of Russian corrugated beams between the flat bending form stability and the strength of the normal section under the action of the bending moment in the plane of the wall.