01149284

Monograph

http://onlinepubs.trb.org...fety/S-08_Final_Report.pdf

This Innovations Deserving Exploratory Analysis (IDEA) project investigated the potential of using laser-based ultrasonic techniques as a basis for a wayside cracked axle detection system. Axle fatigue cracks present an increasing problem in the railroad industry. Service-induced flaws in axles and journals were the fifth leading cause of train accidents in North America between 1999 and 2001. Further, these flaws have been occurring at an increasing rate. Solutions to this problem are a high priority for the railroad industry. In order to decrease the threat of derailment associated with axle fatigue, a method must be designed to either eliminate stress risers, detect fatigue cracks before they reach a critical length, or both. The rail industry has been moving in the direction of using wayside inspection systems as a means of reducing maintenance costs associated with various types of defects and this effort focuses on using laser technology for such a detector. The development approach and testing of the cracked axle detection system included two stages. Stage 1 involved completing an extensive literature review to build on existing knowledge of laser ultrasonic principles and developing laboratory experiments using laser based ultrasonic inspection methods to reliably inspect the axle body for surface breaking fatigue cracks. Stage 2 involved the planning and conducting of a demonstration to prove that laser ultrasonic principles can be effectively applied to the inspection of an axle body in a dynamic environment. Key findings during this demonstration include the following: The laser-based ultrasonic inspection technique is feasible in a wayside environment; More experiments must be completed in order to determine a transducer placement that can reliably inspect the entire axle body; and Laser triggering control will be a design concern in a wayside system.

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Safety IDEA Project 08

English

25p

2006-8

Safety IDEA Program Project Final Report

Final Report

Web

Appendices (1) ; Figures (8) ; Photos (3) ; References (24) ; Tables (1)

Axles; Defects; Fatigue cracking; Flaw detection; Freight cars; Inspection; Lasers; Railroad cars; Remote sensing; Technological innovations; Ultrasonic detectors

Innovations Deserving Exploratory Analysis (IDEA) (Program)

Railroad vehicle axles; Wayside detection systems

Railroads; Vehicles and Equipment; I95: Vehicle Inspection

TRIS, TRB

Jan 28 2010 2:43PM