For studying the influence of crimping defects due to excessive contact resistance on the temperature and stress distribution of cable joints

in this paper

the electromagnetic-thermal-stress multi-physics coupling simulation model of 220 kV high voltage voltage joint under crimping defects is set up in accordance with contact resistance theory based on conductivity and by the use of finite element software. The variation of interface temperature and thermal stress characteristic of silicon rubber insulation in the prefabricated part/high voltage semiconducting composite material under the cable joint crimping defect is studied

the temperature and stress data under different load currents I and contact coefficient k are fitted with multiple functions so to obtain the corresponding calculation methods.The results show that

in case of crimping defect of high-voltage cable joints（for example

contact coefficient k=6）

the thermal stress on the interface of the composite material is distorted by 4.32 times and the degree of secondary distortion of thermal stress is greater than that of temperature.The secondary distortion of the interface thermal stress distribution of composite material is an important cause of the insulation breakdown failure at the end of the high-voltage semiconducting tube.The interface temperature and stress of the composite material of the joint under the crimping defect can be jointly solved by the fitting function or the graphic method.