Sponsor: FRA

PI: Salvatore Salamone

Safety statistics data from Federal Rail Administration (FRA) indicate that train accidents caused by track failures including rail, joint bars, and anchoring resulted in 3,386 derailments and $685 million in reportable direct costs during the decade from 1998 to 2008. The associated indirect costs caused by disruption of service are considered to be at least equally significant. The leading cause of these accidents was the transverse–compound fissure (reportedly responsible for $158 million in direct damage cost and 808 derailments from 1998 to 2008), followed by the detail fracture (DF) (responsible for $136 million in direct cost and 424 derailments during the same period). Transverse fissures (TFs) (initiating at a location internal to the rail head) and DFs (initiating at the head surface as rolling contact fatigue defects), are cracks primarily growing in a plane perpendicular to the rail running direction. In this project we propose a non-contact laser-based vibration measurements instrumentation, for the detection of rail defects in railroad tracks. Specifically, a laser Doppler Vibrometer (LDV) will be adopted in order to record the dynamic vibrations induced by the wheel-rail contact from a moving platform. We hypothesize that the analysis of vibrations, measured in the low frequency range of a rail can be used for flaw detection.