SELECTION OF THE OPTIMAL PARAMETERS OF THE DEVELOPMENT OF THE HEIGHT OF THE TRANSVERSE PROFILE OF PERFORATED ELEMENTS

Abstract

Currently, in the current regulatory documents of Ukraine and Europe, the calculation and further design of metal structures from perforated elements consists in determining the forces in the characteristic design cross-sections, selecting the initial profiles with the simultaneous determination of the geometric parameters of their cross-sections, which in the end would provide the necessary load-bearing capacity. As a rule, it comes down to the calculation of a single-span I-beam with traditional hinged movable and hinged fixed supports at the ends. As the design experience of such structures shows, the development of the height of the original profile by perforation significantly increases their bearing capacity in cross-sections that perceive the predominant influence of the bending moment, and reduces the bearing capacity in those cross-sections where the maximum transverse force acts, since it is mainly perceived by the wall weakened by the perforation. In particular, for a beam on two supports, it is recommended to increase the height of the transverse profile in the middle of the span, where the maximum bending moment acts, by a maximum of one and a half times in the case of using ordinary single-row perforation, and up to 1.7 times, and possibly more, in the case of using checkered perforation or the same in the case of using additional elements to strengthen sections weakened by holes. On the supports of the same beam, where the maximum transverse force  acts, it is recommended to leave the original profile without the development of a cross section or weld the holes obtained as a result of perforation. In the elements of steel structures, such as frames, arches, etc., the combinations of values of bending moment  and transverse force  can differ significantly in the design cross-sections.

The purpose of the article – to theoretically determine the optimal parameters for the development of the height of the initial profile during perforation, as well as to develop an effective method of determining the coefficient of development of the height of the initial profile depending on the combination of internal forces, i.e. bending moment and transverse force, in the calculated cross-sections of the structure or its elements.

Conclusion. The application of the proposed method of calculation allows you to perform rational design of perforated elements from the condition of equality of stresses at the calculated points of the cross section with minimal steel consumptions and at the same time ensuring their bearing capacity.