Effect of surface roughness on sealing performance of silicone rubber

Silicone rubber seals are widely used in the aerospace industry, and the microscopic roughness of the metal surface has a significant effect on sealing performance. In this paper, a sinusoidal profile is used to describe the microscopic topography of the metal surface. Then, a static sealing contact model is developed by the finite-element analysis software Abaqus for analyzing the influence of surface roughness parameters R_a and R_sm on sealing performance. Results show that the sealing clearance and the maximum contact pressures increase when R_a increases. However, the sealing clearance and the maximum contact pressures decrease when R_sm increases. With the decrease in R_a, the contact ratio increases in the contact interface between rubber and metal surface. When R_sm increases, the contact ratio in the contact interface increases. The contact pressure and the stress concentration increase when the surface roughness increases. Thus, it is important to consider the effect of the microscopic roughness in rubber seal design.