THE INFLUENCE OF MECHANICAL FACTORS ON ELECTRICAL TREEING

Emphasis is placed on the growing body of evidence demonstrating the i mportance of mechanical factors in the initiation and growth of electr ical trees in solid polymeric insulating materials. Specimens using po int-plane electrode geometries in homogeneous resins, with and without barrier inserts, have been investigated. The authors draw particular attention to the importance of the adhesive bond between component par ts in composite insulation and the effect that this has on the interna l mechanical stress. The effects of elevated temperatures and the abso rption of moisture on both the mechanical and electrical characteristi cs of these specimens provide additional correlations between treeing and mechanical properties.