Calculation and Analysis on Mechanical Strength of 500kV Hollow Composite Insulator with Different Types of Grooves on the Surface of End Fitting

The impact of different types of grooves on mechanical strength of hollow composite insulators has been calculated and analyzed in this paper to find the proper size and distribution. The investigations have shown that stress concentrations appear in the FRP tube and in the end fitting near the top of the interface. Grooves on the interface between end fitting and FRP tube can decrease the maximum stress of adhesive greatly and the most proper size should be 2mm depth, 8.5mm width and 26mm interval. Besides, different depths cause different concentration of the stress, which may lead to internal fracture.