Influence of Cyclic Tensile Stress on Electrical Treeing in Epoxy Resin

Epoxy resin insulating materials experience complex electromechanical loading conditions. This research examines how cyclic tensile stress influences electrical treeing propagation in epoxy resin systems. Findings reveal that cyclic tensile stress simultaneously generates fatigue deterioration while facilitating internal stress dissipation. Under low stress magnitude conditions, fatigue deterioration predominates, enhancing electrical tree propagation rates as stress frequency increases. Conversely, under elevated stress magnitudes, internal stress dissipation becomes the governing mechanism, reducing electrical tree propagation rates with increasing frequency. Both fatigue deterioration and internal stress dissipation phenomena correlate with the relaxation of physical and chemical crosslinking networks within the epoxy matrix. Strain energy density parameters provide quantitative assessment of cyclic tensile stress contributions to electrical treeing development.