Accurate Evaluation of Interfacial Pressure in Cable Accessories Subject to Nonhomogeneous Degradation

Interfacial pressure is a critical operational parameter for cable accessories, requiring accurate evaluation throughout service life. However, the non-homogeneous degradation induced by radially gradient-distributed mechanical stress significantly complicates this evaluation. This study investigates the influence of stretching ratio on the stress relaxation behavior of silicone rubber. A non-homogeneous operational model for cable accessories is established to accurately evaluate interfacial pressure evolution. Comparative analysis with traditional homogeneous models reveals that although both systems exhibit comparable long-term interfacial pressure reduction patterns, their degradation rates differ substantially. Crucially, a characteristic point is identified where interfacial pressure behavior converges in both systems, enabling simplified prediction of pressure variation in actual non-homogeneous degradation conditions using homogeneous approximations.