PREREQUISITES FOR PREDICTING THE WORK OF PASSIVELY REINFORCED BENDING WOODEN ELEMENTS WITH METALLIC MATERIALS

Abstract

A detailed analysis of literary sources on the strengthening of solid and glued wooden elements of rectangular cross-section was carried out. Based on the literary analysis, the purpose and objectives of the research are given.
 It is possible to distinguish two methods of manufacturing reinforced wooden structures: the first method is a passive method of using reinforcement, where reinforcement is used in bending wooden elements without prestressing; the second method is active, where the reinforcement is prestressed in the bending element.
 In order to consider this problem comprehensively, it is necessary to have mechanical properties of wood and reinforcement (metallic and non-metallic), mainly deformable and strength characteristics. In particular, such parameters should apply to critical indicators, i.e. indicators that correspond to the maximum stresses of the materials under study.
 To establish the stress-strain state of the cross-section of the reinforced element, as well as for the unreinforced element, it is necessary to specify two functions "stress-strain" of wood under axial compression and tension. Also, the two functions of metal work in compression and tension. 
 The expediency of reinforcing elements made of solid and glued wood with steel reinforcement is substantiated. The basic prerequisites for the reinforcement of a wooden element working on transverse bending with metal materials have been established. The stress-strain state is established for wooden elements with reinforcement of the compressed and stretched zone. An algorithm has been developed for the use of various functions to determine the stress-strain state of wood, as well as to construct a "moment-curvature" graph for various types of wood reinforcement with metal materials.
 The need for further experimental and theoretical research is substantiated.