Simulation Research on Interface Pressure of Cold Shrinkable Joint of Distribution Cable

Abstract

With the advantages of reasonable volume, simple installation and wide application range, the cold shrinkable cable intermediate joint has become the main form of distribution cable intermediate joint at present. It relies on the interference fit between the cold shrinkable tube and the cable body to generate interface pressure, so as to ensure the insulation strength and sealing performance of the joint. Too large or too small interface pressure will affect the safe and stable operation of the joint. Therefore, it is very important to master the interface pressure distribution of the joint and keep the interface pressure at a certain level and evenly distributed to ensure the safe and reliable operation of the joint. In this paper, the finite element simulation model of the cold shrinkage intermediate joint is established, and the distribution of the interface pressure is simulated and analyzed by Yeoh fitting. The results show that the interface pressure is symmetrical along the axial direction. The interface pressure is the largest at the semi conductive layer and the smallest at the insulating layer. At the same time, the influence of different interference on the interface pressure is analyzed. For the simulation model in this paper, the interface pressure increases by about 0.12 MPa when the interference increases by 1mm. The smaller the interference, the more uniform the interfacial pressure distribution along the axial direction. Therefore, under the condition of meeting the insulation strength requirements at the interface, the cold shrinkage intermediate joint with small interference can be selected, so as to slow down the speed of stress relaxation and improve the service life of the joint.