The manufacture and repair of mechanical engineering products and other industries is associated with the qualitative preparation of their surfaces for the application of protective non-metallic coatings on them, which ensures an increase in their durability and reliability. Among the methods of cleaning metal surfaces, the environmentally friendly and energy-saving crushing process occupies a priority place. Therefore, it is important to substantiate aspects of the destruction process of the metal products’ surface layer of mechanical engineering during shot blasting, depending on the process parameters, which allows more rational planning and a balanced technology for high-quality surface preparation of products. The results of experimental and analytical studies of the mechanism of destruction of the surface layer of steel specimens attacked by a shot, as well as a shot torch, depending on the specified parameters: angle and speed of attack, shot diameter and mechanical properties of the material are presented. The destruction coefficient is related to the ratio of the trace volume left by the pellet on the attacked surface to the pellet volume, which integrates the result of dynamic contact. The results obtained indicate that the degree of destruction intensity does not depend on the diameter of the shot and reaches a maximum at angles of attack at a given speed. The analytical setting of the destruction coefficient allows, without unnecessary technological samples, to balance the process parameters to achieve the required quality of surface cleaning at the lowest possible cost.

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An exact analytical solution is presented for the problem of plane transverse bending of a segment of a narrow multilayer circular arch subjected to a normal uniformly distributed load on its longitudinal surfaces. The solution is constructed using the superposition principle based on the general solutions obtained by the authors for the bending problems of multilayer cantilevers with a circular axis under the action of loads on the free end and a uniformly distributed normal load on the longitudinal surfaces. Methods for modelling different types of end restraints for multilayer arches are considered: rigid, hinged, and combined. Using the example of a five-layer arch with varying restraints at the end, the influence of transverse shear deformations on the deflection and normal stresses is analyzed. The obtained relations allow determining the stress-strain state of multilayer arches with an arbitrary number of homogeneous (orthotropic, isotropic) layers, taking into account transverse shear and compression deformations, and can be used to construct other important solutions to arch deformation problems and develop more universal methods for calculating such structural elements.