Researching of wooden beams with external reinforcement based on toothed steel plates

The main element of the technology proposed in the article for reinforcement wooden beams is an external reinforcement based on a metal toothed plate, which is a steel strip with stamped, forward-bent perpendicularly teeth. A method for calculating wooden beams reinforced with metal toothed plates (MTP) propose following the theory of calculating composite rods by A.R. Rzhanitsyn, considering the ductility of the connection at the “beam-plate” border and the size of the stretched zone of the beam by the plate when creation in it prestressing it before pressing. The calculation of the beam, reinforced with the MTP, installed symmetrically in the middle of the span from the side of the stretched zone of the cross-section, has been carried out, the calculations of the edge stresses in the compressed and stretched zones, as well as the vertical displacements of the beam, have been done. 2 types of metal toothed plates, differing in the thickness of the base, as well as the size and shape of the teeth have been considered. Conclusions have been formulated about the influence of the type of plates, the length of the reinforced section of the beam and the magnitude of the prestress on the increase in the strength and deformative characteristics of the reinforced element.