Investigation of the electrical rolling contact degradation based on fractal theory

Fractal contact resistance model of wind pitch slip ring considering wear and self-excited vibration

“…When the currents flow through the conductive spots, it is assumed that the contraction resistance R c of a single asperity contains only the Sharvin resistance R s and Holm resistance R H . R c is the solution of a Laplace equation and can be described as (Kogut and Komvopoulos, 2003; Niu et al , 2020): where, ρ 1 and ρ 2 are the resistivities of the friction pair, r = a 1 /2 / π 1/2 , r is the radius of the real contact area a , λ is the average electron mean free path.…”

“…The micro asperities with different sizes are distributed on the contact surface. The fluctuation of the contact resistance is closely related to the contact area of the asperities, which will affect the transmission efficiency of the slip ring (Lin and Chang, 2011; Zhu and Li, 2020; Niu et al , 2020). Thus, the study on the contact resistance of the slip ring is the basis to improve the transmission quality.…”