Theoretical Substantiation of the Initiation and Direction of Crack Development under Impact Loading of the Elastomer Surface by Solid Particles

A theoretical model of the formation of the stress-strain state in elastomers under the action of a concentrated load is considered. Experimental studies were carried out using the polarization-optical method. As a sample, transparent L-83 polyurethane with physical and mechanical characteristics corresponding to typical rubbers was used. It is shown that the stress-strain state of the surface layer calculated as a result of the theoretical solution of the mathematical model coincides with the experimental data. When loading, zones of compressive and tensile stresses are created. The magnitude of the tensile stress determines the likelihood of surface destruction (tearing). Simulation of an oblique impact confirmed the qualitative picture of the stress-strain state in elastomers under the action of a concentrated load. A theoretical study made it possible to establish that the potential energy of deformation is distributed over the depth of the surface layer in inverse proportion to the square of the distance from the point of application of the force, i.e., the point of contact of the solid particle with the surface of the elastomer. This makes it possible to mathematically calculate the level and distribution of energy dissipation in the wear volume of the surface layer. Theoretical and practical studies have shown that in the practical use of elastomer linings, it is recommended to install them at an angle close to 90° to the direction of solids flow.