АНАЛІЗ УШКОДЖЕНОСТІ МАТЕРІАЛУ КОНСТРУКЦІЙ

Abstract

The ability of materials to retain the required set of properties under the action of operational loads on the structure is determined by the structural changes that occur under such loads. From the first days of operation, under the influence of force factors, the environment and time, the strength and deformation properties of structures of buildings and structures change. The solution to the main task of construction science - reducing material consumption in construction, is inextricably linked with the need for constant study and refinement of the strength and deformation characteristics of building materials and structures, as well as a change in their bearing capacity over time and an assessment of the working capacity (resource) reserve when setting an external power load. Based on the fundamental position that under the action of a load, a deformation process occurs in the construction material, which is accompanied by irreversible processes of their appearance, development and accumulation of damage to the structure of the material, and, as a result, leads to destruction, we come to the conclusion that it is necessary to carefully study the strength of wooden designs taking into account this phenomenon. There is a need to comprehensively study the issues of damage accumulation in wooden structures under the action of loads and the related processes of changing the cross-sectional area and bearing capacity, to use the research results when calculating structures. This makes it possible to reduce material consumption and make the sections of wooden structures more economical and avoid excessive safety margins. Therefore, an important manifestation is the fixation of cracks and internal interfaces, which allows one to quantify the integral damage of the structure material to predict their safe functioning. The authors considered analytical dependences for the description of disseminated injuries that follow from physical considerations or are constructed from some mechanical models of the process of long-term damage. Three main types of models have been identified: force, deformation and energy. Experimental studies of normal stress diagrams make it possible to visually record the formation of folds in the compressed zone, as well as calculate the value of the instantaneous elastic and viscoelastic components of total deformation. A measure of the accumulation of damage in a material is damage. In this work, the damage was calculated based on the known specific parameters of the material: deflections, relative deformations and changes in the number of acoustic emission signals. The graphs of the dependence of damage on the load were built: - on the development of deflections; - on the development of fibrous deformations; - on the development of deflections and acoustic emission (relative load); - on the development of fibrous deformations (relative load); This scientific work is a logical continuation of previous studies of damage to wooden structures. The article presents the results of experimental studies of the strength, deformability of wooden beams under the influence of a static load. The direction of improving the methodology for designing wooden structures and determining the residual resource has not been reflected in the technical literature. Therefore, it is necessary to conduct a comprehensive study of them.