Insulation defects such as residual stress

tiny bubbles and cracks are one of the important factors leading to the failure of gas insulated metal enclosed switchgear (GIS) insulators over the past 40 years. The mechanism of residual stress

bubble generation and crack propagation of epoxy composites and metal-epoxy interface during the curing process of GIS insulators has not been mastered. Its technical bottleneck is the lack of effective detection methods. In this paper

the curing characteristics and defect generation mechanism of GIS insulator are analyzed and studied as follows: the first is the curing characteristics and defect generation mechanism of epoxy composites for GIS insulator; the second is the curing characteristics and defect generation mechanism of metal-epoxy interface for GIS insulator; the third is the defect detection method of GIS insulator. Among them

the curing characteristics of epoxy composites include gel time

gel temperature

glass transition temperature

curing degree

and residual stress/strain. The research on the defect generation mechanism of epoxy composites includes the multi-physical field coupling model of chemical-thermal-curing strain

bubble activity mechanism

and crack propagation phase field model. The generation mechanism of air gap defects at the metal-epoxy interface includes stress concentration during the curing process. The process and formula improvement methods of material and interface defect inhibition include curing temperature/time

filler

model

ratio

and interface treatment process. The defect detection of insulators include X-ray test

pulse current method

ultra-high frequency method

and ultrasonic nondestructive technology. The detection of epoxy curing characteristics includes differential scanning calorimetry and fiber Bragg grating technology. Finally

it is pointed out that the fiber Bragg grating technology can be adopted to not only provide digital monitoring and manufacturing technology for GIS high-performance insulators by monitoring multiple curing characteristics of epoxy composites

but also provide experimental technology for revealing process mechanisms such as chemical-thermal-curing strain multi-physics field coupling

bubble activity

and crack propagation.