The design of high voltage cable accessory is a complex process involving electric

machinery

material

and thermodynamics. The electrical

mechanical and thermal composite field is precisely designed to minimize the failure rate caused by production process. Consequently

we discussed several key design problems such as the electrical properties

mechanical properties

relaxation characteristics

expansion deformation and electric field optimization in high voltage prefabricated or shrinkable cable accessories. We proposed that accessories expansion rate would decrease with rubber elasticity modulus and increase of interfacial pressure

and rubber stress relaxation rate would increase with environment temperature and rubber elongation increasing. The expansion of the cable accessory brings a nonlinear displacement from the inside to the outside

and the inside displacement is large and the outside is small. Based on the theory of the elastic-plasticity mechanics

the thick-wall cylinder deformation equations of cable accessories were established. The production structure could be obtained by the relaxation process of the accessory

recovering from the expanded installation state after electrical field optimization. Finally

a reasonable method to design cable accessories production was proposed. The method is expected to guide the structure optimization design and material selection of high voltage AC and DC prefabricated/shrinkable cable accessories.