ANALYSIS OF THE STATE OF STRESS AND DEFORMATION OF GLAMINATED WOOD FRAMES REINFORCED WITH COMPOSITE TAPES

Abstract

In the modern world, the construction industry is successfully developing in various directions. Large-sized structures are replaced by analogues reduced in cross-section with the help of various types of reinforcement.
 Frames refer to flat spacer structures. Modern glued frames are often solid. Cross-section (lattice) structures of this class were used mainly from solid wood. Currently, they are practically not used due to the lack of their industrial production.
 Frame structures mainly consist of rectilinear elements and allow the presence of rigid (frame) nodes. Rigid nodes of three-hinged frames are usually called eaves, because they have to be constructed exactly under the eaves of the building. These units ensure joint operation of crossbars and racks, which reduces bending moments in the crossbar. In addition, it is easily proven that the maximum bending moment in the cornice nodes of the frames is less than the maximum moment in the beams with the same spans. Their ratio is equal to the ratio of the height of the frame strut to the arrow of the rise of the ridge joint relative to the support joints. Accordingly, unlike beams, frames can cover larger spans.
 However, it is the eaves units that have the largest cross-section in frames made of glued wood, which requires significant material consumption. Therefore, research in the field of strengthening such nodes to reduce their cross-section is relevant.
 Composite materials are currently one of the leaders in strengthening structures because most composite materials are well resistant to many chemical influences: alkalis, acids, chlorides, sulfates, nitrates, and others. This allows them to be used both in industrial and agricultural construction, where there is a direct impact of the external environment on the structure reinforced with composite materials, and in residential buildings without harm to residents.
 After analyzing the stress-strain state by modeling in the LIRA CAD software complex of broken-glued three-hinged frames made of glued wood with integrally glued eaves nodes with a crossbar connection with a rack through toothed spikes along the bisector of the corner reinforced with composite tapes and comparing with similar frames without reinforcement, we can to conclude that such materials can be perfectly combined with structures made of solid and glued wood, allowing to increase the load-bearing capacity while reducing their cross-section.