The mechanical strength of unreinforced abrasive wheels is determined by centrifugal and bending forces, but their distribution during reinforcement is unknown. It was assumed that the stresses are distributed evenly, but a comparison of calculations on the theory of elasticity and real characteristics on a special stand showed complete discrepancy. Tensile tests of the wheels made it possible to compare the stresses results in the circumferential and radial directions. Was found that the reinforced wheel is an anisotropic body. Anisotropy can be reduced by displacing one reinforcement mesh relatively to the other by angle of 45°. In this paper, a mathematical model of the stress-strain state of the abrasive reinforced wheel was developed, taking into account the anisotropy of its properties. To determine the centrifugal forces, the theory of elasticity for an orthotropic body is applied. The bending forces that arise in the working wheel were determined during solving the problem of the distribution of deformations in the anisotropic annular plate rigidly fixed along the inner contour. As a result of experimental studies, it was found that stresses reach 8...23 MPa, which can be compared with the ultimate strength of the wheel matrix. The elastic module of the wheel matrix is noticeably greater than the elastic module of the reinforcing mesh, which practically does not perceive the load at the initial stage. The developed mathematical model of the strength indicators for abrasive reinforced wheels makes it possible to predict their reliability and safe operation.

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Київський національний університет будівництва і архітектури (КНУБА)Повітрофлотський просп. 31, Київ, Україна, 03680,

Carrying out of the clearing operations at carrying out mechanized processing of construction equipment from paints and varnishes, rust, various kinds of pollution belongs to mass labour-consuming operations [1]. To carry out these operations, widespread use of hand-held machines, working bodies that have abrasive wheels and metal brushes. The versatility and versatility of these machines, combined with the correct selection of the desired abrasive work tool, can significantly accelerate and facilitate the performance of cleaning and grinding operations with the desired effect. However, most of them have drawbacks in the cleaning of thin-sheet metal, since the removal of the base metal also takes place, which in most cases is not acceptable. So when processing non-metallic materials with metal brushes the working surface is clogged with small particles of metal, which subsequently leads to the formation of rust, and when cleaning the metal surfaces grooves are formed. Metal brushes are also ineffective in cleaning surfaces of synthetic enamels, curvilinear surfaces and inaccessible areas. Machining these tools is energy-intensive and requires the use of heavy-duty hand machines. Fiber and petal abrasive tools are not self-cleaning and lose their cutting power due to the filling of the intergranular space with cleaning waste.  Sand blasting is environmentally hazardous for workers and the environment, since the sand consumables fly over long enough distances (especially when clearing tall structures and structures). The analysis showed that one of the effective tools for cleaning metal and non-metal surfaces from paint coatings, rust and other contaminants without removing the base material layer is a polymer-abrasive brush. However, there is insufficient research on the mechanism of its operation, energy and thermal processes that occur during operation and have a decisive influence on the performance of the polymer-abrasive brush. The results of studies of the influence of structural and mode parameters of manual angle grinders with polymer-abrasive brushes are presented in the paper. The study of these issues is an urgent task, as it will allow to determine the parameters of the drive machine, rational modes and schemes of their operation, as well as the scope of use of such working bodies.