Nonlinear elasticity of rectangular elastomeric seals and its effect on elastohydrodynamic numerical analysis

Elastomeric seals used in high-pressure hydraulic systems obey complex stress–strain laws when sufficiently strained, which occurs for high sealed pressure and large temperature differentials. Such seals often operate in extreme environments of pressures up to 35 MPa (5000 lb/in.2) and temperatures in the range of −60 to +140 °C. For the elastohydrodynamic numerical analysis of these seals, it is imperative that the rubber behaviour under stress is properly described with a suitable stress–strain model, such as the popular Mooney–Rivlin model. Such a nonlinear model is developed and tested in this study to produce important numerical results for the seal performance (contact pressure and width, film thickness, leakage rate and friction). The nonlinear model is then compared with the classic Hookean model of linear elasticity in order to establish the differences of the models and the limits of applicability and validity of each one for a wide range of operating conditions.