Analysis of Brittle Fracture of Composite Insulators by Using Finite Element Technique

The Brittle fracture process causes cracks on the FRP rod of the Composite (Composite) insulator that leads to premature failure of Composite insulators. Major types of stress affecting the service life of an insulator are electrical, mechanical and environmental stress whereas the major physical threat is vandalism. For various transmission and subtransmission voltages, the insulators are required withstand the maximum tensile strength of the conductor. Therefore, understanding the mechanical stress withstanding capability of Composite insulator is important. Proper designing of the strength of FRP (Fibre Reinforced Plastic) rod is most important. FEA (Finite Element Analysis) analysis of voltage distribution along the length of the Composite insulator is also necessary for the understanding of electric field stress required for surface deterioration of Composite insulator. The mechanical stress analysis for various cross sections of FRP rods for a given mechanical load has to be carried out in order to optimize the diameter of the FRP rod for better reliability. FRP rods of different diameter were considered, it is observed that when diameter is increased the maximum stress is reduced and hence, by increasing the diameter of FRP road better results can be obtained. It is also observed that displacement is more in FRP rod of lower diameter.