Heat checking in the contact zone of a face seal: A three-dimensional model of a single moving asperity

Heat checking phenomenon in mechanical seals resulting from the passages of a single asperity over the face of a seal ring has been solved with a thermomechanical model of a semi-infinite medium subjected to the frictional heat source over the moving contact zone. An earlier analysis of such a problem was based upon a two-dimensional model of a single moving asperity. Such a load resulted in fracture which is initiated beneath the surface at the trailing edge of the moving load. For a better description of the physical problem, a three-dimensional model is examined in the present study. A single moving asperity, with a circular or a rectangular geometry of the contact area, is assumed on the mating part of the seal face. The general solution is obtained for any distribution of contact loads. Numerical solutions are obtained for uniform and parabolic distributions of pressure over the circular and rectangular contact zones. The traverse speed of the friction load is considered the same as the rubbing speed for the current problem. The roles of material properties and operating variables are delineated in terms of dimensionless parameters. The analytical solutions of the mechanical and the thermal stress fields are solved by means of the double Fourier transforms. The temperature field is obtained by the use of the Green's functions. Numerical results of the corresponding integral solutions are represented in graphs.