On the influence of the pipe outer coating nonuniformity on the contact stresses arising under rigid bushes

The work is devoted to the formulation and construction of a solution in analytical form for the mechanical problem of contact interaction between a finite system of rigid cylindrical bushes and a pipe with an external coating, which has longitudinal nonuniformity. In industry and mechanical engineering, the presence of such additional coatings is required, for example, for protection the pipe main layer from external aggressive media, for its electrical or thermal insulation, etc. The nonuniformity of such a layer may be due to various additional requirements, as well as the obtaining process of this layer. When analyzing the stress-strain state of the pipe interacting with the bushes, it is necessary to take into account all the features. The paper shows that the mathematical model of the above-described interaction problem is a system of mixed integral equations containing integral operators of different types. Moreover, the resulting system includes functions describing the variable properties of the outer layer in the area of interaction with the bushings. The special approach described by the main theses in this paper makes it possible to obtain a solution in a form in which all complex functions are allocated as separate multipliers. This makes it possible to perform calculations even in cases where the coating is highly heterogeneous or consists of different materials.