Contact stresses in rotating bodies with regard for heat generation and convective heat exchange
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CONTACT STRESSES IN ROTATING BODIES WITH REGARD FOR HEAT GENERATION AND CONVECTIVE HEAT EXCHANGE R. Kul’chyts’kyi - Zhyhailo
UDC 539.3
An axisymmetric contact problem of thermoelasticity for rotating bodies is analyzed with regard for heat generation in the contact region and convective heat exchange between the bodies and the ambient medium. The distribution of stresses in the bodies is determined. Special attention is given to the maximum tangential stresses and the possibility of appearance of tensile stresses.
The influence of heat generation on the parameters of contact (the sizes and shape of the contact region and the distribution of contact pressure) in two-dimensional, axisymmetric, and three-dimensional contact problems of thermoelasticity is well studied [1–13]. Thus, it is shown that the contact region noticeably depends on the intensity of heat generation and can be much smaller than in the corresponding isothermal contact problems. This definitely increases the level of contact pressure and, therefore, promotes the growth of the maximum tangential stresses. The cited investigations are mainly restricted to the analysis of the distribution of contact pressure and the sizes of the contact region. At the same time, the stresses formed as a result of the superposition of stress tensors caused by loading and local heating of the surfaces of the bodies are studied quite poorly. The axisymmetric and tree-dimensional contact problems are solved under the assumption that the unloaded surfaces of the bodies are thermally insulated [1–3, 8, 9, 12, 13]. This assumption is true if it is necessary to determine only contact characteristics because, as indicated in [10, 11], heat exchange with the ambient medium weakly affects the contact region and the distribution of contact pressure. Moreover, under certain conditions (either one of the bodies is a thermal insulator, or the Biot coefficients of the surfaces of the bodies are equal, or the thermal properties of the bodies are identical, or the heat exchange is very intense and the temperature of the unloaded surface of the body is equal to the ambient temperature), it is possible to prove that the above-mentioned contact characteristics are absolutely independent of the heat exchange with the medium. However, it would be incorrect to say that the process of heat exchange does not affect the stresses acting in the bodies. Indeed, numerous parameters of the stressed state (including the first principal stress and the maximum tangential stress) strongly depend on the intensity of heat exchange. In what follows, we study the influence of heat exchange with the medium on the distribution of stresses in rotating bodies [1, 3]. Our attention is focused on the distributions of the first principal stress and the maximum tangential stress. The indicated characteristics play an independent role in numerous fracture criteria. They can also be used for the verification of some other (more complicated) criteria, e.g., of the criterion based on the construction of the stress f
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