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A spatial quasi-static contact problem for a spherical hinge joint is considered. On one of the sliding surfaces, a thin polymer composite cover is coated. The polymer matrix is based on a C-2 phenylone and fillers in the form of fine F4MB fluoroplastic powders, tungsten-molybdenum blue, and a C-52 cylinder oil. To solve the problem, the finite-element method and the ANSYS software package were used. The Archard model was employed for describing the wear process. The stress-strain state of the joint was investigated, and the linear wear of the coating at the initial stage of interaction of faces was determined under the same loading conditions and coating thickness. It was found that, at the initial moment of time, the contact pressure and the equivalent stress in the interaction zone increased, which was associated with the “running-in” stage, when the contact was formed when the die unwinded. With reaching a stable rotation mode and a gradual increase in the area of contact patch, due to wear, these values decreased. The amount of wear at the initial stage changed almost linearly and directly depended on the wear factor. The volumetric wear was obtained for different coatings, which allowed us to calculate the rate and intensity of wear.

The work presented is devoted to the axisymmetric contact problems on the interaction of a rigid stamp and an elastic layer fixed on a porous elastic half-space by using the Cowin–Nunziato model. It is assumed that the stamp basis has a flat or parabolic shape and friction is absent in the contact zone. With the help of the Hankel integral transform, the problems stated are reduced to solving integral equations for the unknown contact stress by using the collocation method. The values of contact stresses and the contact area in the case of a parabolic stamp are found. The normal stresses on the interface between the elastic layer and the poroelastic half-space are investigated. The relationship between the force acting on the stamp and the corresponding displacement, which is one of the main characteristics in determining the mechanical parameters of the material by the indentation method, is investigated. A comparative analysis of the values found for various parameters of the elastic layer and the poroelastic base is carried out. The numerical results are presented in a table and in the form of graphs.

The nonlinear static problem of FEM modeling of a damaged pipeline repaired by a composite material and subjected to internal pressure is considered. The calculation is carried out using plasticity theory for the pipeline material and considering the polymeric filler and the composite wrap. The level of stresses in various zones of the structure is analyzed. The most widespread alloy used for oil pipelines is selected as pipe material. The contribution of each component of the pipeline-filler-wrap system to the level of stresses is investigated. The effect of the number of composite wrap layers is estimated. The results obtained allow one to decrease the costs needed for producing test specimens.