Mechanical Property Analysis, Simulation and Theoretical Calculation of Silicone Rubber Joint Assembled in HV Cable under Certain Circumstances

High voltage cable accessories play important roles in the power system. Due to the limitation of laying conditions, in some cases, the cable may bend at a certain curvature at the cable joint. The interference fit between the cable joint and the cable is used to form the interface pressure, and the curved state of the cable joint will cause the interface pressure to deviate from the preset value (locally larger or smaller). Aiming at the above problems, in this paper, the model parameters of silicone rubber and semiconductive rubber for 110kV cold-shrinkable cable accessories were calculated by the uniaxial tensile test and the selection of Yeoh model. Based on the constructed nonlinear model of rubber materials, the interface pressure distribution results of the 110kV cable joint before and after bending were analyzed by using finite element simulation software and mechanics theory. The results show that Yeoh model is more suitable as a constitutive model for silicone rubber and semiconductive rubber under uniaxial tensile test conditions. When the cable joint is over-assembled on the cable, the interface pressure is symmetrically distributed along the axial direction. The interface pressure from the root of the stress cone to the end of the high-voltage shielding tube is slightly fluctuated and the interface pressure of the region is smaller than that of the highvoltage shielding tube. When the cable joint assembled on the cable is curved with a certain curvature, the interface pressure in the middle area of the upper surface of the cable joint becomes larger, and the interface pressure at both ends decreases. On the contrary, the interface pressure in the middle area of the lower surface of the cable joint becomes smaller. The interface pressure at both ends becomes larger.