Failure Modes Of Insulators Under Multi-factor Coupling

In actual operation, suspension type insulator faces the combined effects of multiple deterioration factors. Ultraviolet radiation causes photodegradation of the polymer chains on the sheath surface, gradually reducing tensile strength. Corrosive media such as acid rain cause ion exchange with the glass fibers, resulting in microcracks on the fiber surface due to volume changes. When the fibers are subjected to tensile loads, these cracks propagate rapidly.

Stress corrosion mechanism explains the brittle fracture process of the composite tension insulator mandrel: under the combined action of an acidic environment and continuous tension, even if the load does not reach the conventional failure threshold, the material may still fracture suddenly. Cracks initiate from the resin matrix, propagate perpendicular to the direction of force, and temporarily stop upon encountering the fibers. As the corrosive medium penetrates deeper into the crack, the fibers break one by one, and the average stress in the remaining cross-section continuously increases, eventually leading to the overall failure of the high voltage transmission line insulators core.

The overhead power line insulators core retains relatively good performance in the middle and low-pressure sections, while the mechanical properties of the high-pressure section show the most significant degradation. This performance gradient distribution confirms the differentiated effects of electric field strength, environmental factors, and mechanical load in different regions.

Regular inspection and performance evaluation are means to prevent unexpected failure of tension insulator. Ultrasonic testing can identify delamination defects inside the dead end insulators mandrel, and dye penetration testing can detect areas with poor interfacial bonding.