Analysis of Stress Relaxation Characteristics of Rubber Sealing Gaskets Under the Influence of Random Parameters

The Mooney–Rivlin hyperelastic model and Prony series viscoelastic constitutive model are used to verify the selected calculation parameters by finite element analysis compared with stress relaxation test data. Then, the ANSYS-PDS (ANSYS-probabilistic design system) module is used to analyze the sensitivity values of all random parameters to surface contact stress and the influence of hyperelastic and viscoelastic parameters on the surface contact stress relaxation. The results show that parameter values are reasonable. Random parameters that have great influence on the surface contact stress are α2 and C10, followed by α1, τ1 and C01, and the influence of τ2 is negligible, which shows that for the second-order viscoelastic model, the change in clay pot coefficient η2 has little effect on the surface contact stress. Moreover, with the increase in C10, the surface contact stress increases significantly; with the increase in α2, the surface contact stress decreases significantly, and the surface contact stress varies uniformly with C01. Stress relaxation mainly occurred on the first day of loading and remained basically stable within 1 year. The greater the values of hyperelastic parameters are, the smaller the stress attenuation is, and the opposite of viscoelastic parameters.