RESEARCH OF BEARING CAPACITY OF SINGLE-ROW AND DOUBLE-ROW CASTELLATED BEAMS OF DIFFERENT CONFIGURATIONS

The article considers the issue of estimation and technology of beams manufacturing with single- and double-rows perforation of the web with round holes. In particular, the national and foreign experience of constructing facilities with castellated beams is analyzed. The issue of potential reserves for weight decrease of the beams is considered. It is shown that the types of castellated beams are quite diverse and are associated with different configurations and numbers of cutting lines, and as a result with different shapes and sizes of holes. In order to determine the influence of various parameters of structural design, in particular single-row and double-rows perforation of the web on the stress state, bearing capacity and stability of beams modeling of perforated beams with single-row and double-rows web perforation is carried out. For the beams with the insignificant section sizes between round openings, the mesh of finite elements with their essential concentration in zones of holes is carried out. The castellated beams were estimated using the finite element method. It is shown that the influence of circular holes is essential for ensuring the strength, rigidity and efficient operation of cellular beams. A comparative analysis of beams with single-row and double-rows perforation of the web with holes having equal diameters is conducted. It is determined that a more uniform distribution of material in the web of the beam with double-rows perforation increases their rigidity and stability in comparison with single-row perforation with the same weight of structural elements. Based on the research, rational design solutions for castellated beams with single-row and double-rows perforation are proposed based on the criteria of ultimate strength, rigidity and stability.