Modeling the operation of wooden beams modified with epoxy resin after exposure to single and low-cycle loads using the finite element method

Abstract

As load-bearing structures of industrial and civil buildings and structures, bridges and bridge crossings, tunnels, scaffolding of underground mines, in most cases coniferous wood species are used. These include spruce, fir, fir, pine, larch and others. In many cases, such structures must work with increased mechanical characteristics. It is possible to improve the properties of wood by modifying it. There are various methods of modification that can increase the strength of wood by 20-300%. Some of these methods can be used to modify load-bearing structures, in particular, beams, trusses, columns and others. The operation of elements and structures made of wood under various loads and influences can be modeled based on the finite element method. Such modeling, as a rule, was carried out for unmodified elements and structures. In this work, we will be interested in the prediction and numerical modeling of the operation of solid pine wooden beams modified with epoxy resin by the finite element method after the action of single and low-cycle loads. The purpose of these studies is to model the operation of rectangular pine wooden beams modified with epoxy resin after the action of single and low-cycle loads by the finite element method based on the mechanical characteristics of materials. Numerical modeling of the operation of unmodified and epoxy resin-modified rectangular pine beams with a cross section of 50x80x1650 mm after the action of single and low-cycle loads by the finite element method in the LIRA SAPR software package based on the mechanical characteristics of materials. The stress-strain state of bending elements made of pine wood modified with epoxy resin and unmodified after the action of single and low-cycle loads was established. Based on the numerical simulation of the studied bending elements, isofields of longitudinal stresses, vertical displacements, and shear stresses were constructed, respectively, after the action of single and low-cycle loads. It was established that at all loading levels, a decrease in vertical displacements was observed in beams using epoxy-modified pine wood of solid cross-section, both under single and low-cycle loads. Based on the numerical simulation, it was determined that the bearing capacity of epoxy-impregnated wooden beams of solid rectangular cross-section increases significantly compared to unimpregnated ones, both under single and low-cycle loads. In the future, it is necessary to conduct experimental and theoretical studies in this area of research and to compare them with the numerical study conducted in this work..