The frequent failures of cable accessories in low-temperature environments indicate uncertainties in the interfacial mechanical reliability. On the basis of silicone rubber (SiR) materials for cable accessories

we investigated the low-temperature crystallization characteristics and stress relaxation behavior of SiR under varying temperatures (from room temperature to low temperatures). The effect mechanism of the strain-induced crystallization (SIC) on the mechanical properties of SiR at low temperatures was analyzed. A calculation formula for entropic elasticity under temperature variations was derived using the rubber state equation

and the influence mechanism of low-temperature conditions on the mechanical properties of SiR insulation in cable accessories was elucidated. The results indicate that the SIC effect leads to a significant surge in stress within SiR insulation under extreme low-temperature conditions

accompanied by an elevation in crystallization temperature. The stress variation observed in silicone rubber under a constant tensile ratio during cooling is primarily attributed to contributions from entropic elasticity. At medium-to-high tensile ratios (125%≤λ≤400%)

the stress behavior of SiR is dominated by the Gough-Joule effect

which manifests as a progressive decrease in stress with decreasing temperature. This phenomenon is identified as the underlying cause of unreliable interfacial pressure in cable accessories operating in low-temperature environments. Actual calculations of interface pressure between cable and accessory have also confirmed that the interface pressure under extreme low-temperature conditions decreases below the critical safety threshold of 0.1 MPa. The research results can be used for evaluating the mechanical reliability of rubber insulation used in cable accessories under low-temperature environments.