The low adhesion problem: The effect of environmental conditions on adhesion in rolling-sliding contact

Abstract

Low adhesion problem is one of the major problems for railways all over the world because this phenomenon can occur anytime and anywhere. To investigate when poor adhesion conditions can be expected in real operation, a ball-on-disc tribometer with a climate chamber was employed to simulate rolling-sliding contact under various environmental conditions. Clean and contaminated discs with leaf extract were used to simulate different surface conditions. Results indicate that contact operating under rolling-sliding conditions is more prone to the occurrence of low adhesion than found by others for pure sliding contact. Very low adhesion (0.05) were identified for contaminated and oxidized specimens operating under humid and wet conditions. For clean surfaces, low adhesion (0.15) were found under dew conditions.

Low adhesion problem is one of the major problems for railways all over the world because this phenomenon can occur anytime and anywhere. To investigate when poor adhesion conditions can be expected in real operation, a ball-on-disc tribometer with a climate chamber was employed to simulate rolling-sliding contact under various environmental conditions. Clean and contaminated discs with leaf extract were used to simulate different surface conditions. Results indicate that contact operating under rolling-sliding conditions is more prone to the occurrence of low adhesion than found by others for pure sliding contact. Very low adhesion (0.05) were identified for contaminated and oxidized specimens operating under humid and wet conditions. For clean surfaces, low adhesion (0.15) were found under dew conditions.