Advanced Ultrasonic Techniques for Railroad Inspections

Laser generated ultrasound and air-coupled ultrasonic
detectors are used to develop an inspection technique
for the railroad industry. The Laser Air Hybrid
Ultrasonic Technique (LAHUT) has the advantage of
performing inspections without establishing contact
with or the need to come close to the inspected
structures. This feature makes it possible to perform
dynamic inspections of tracks from a moving train and
stationary wayside inspection of wheels on a passing
train. The study considers the most critical flaw
types in railroad tracks and wheels. Some are very
difficult to detect with currently available
technology, others are not possible without a
handheld device. The second part of the book uses a
contact ultrasonic method to monitor microstructural
effects during fatigue cycling of railroad steel. Two
experiments configurations are presented. One is very
sensitive to microcracks. Once detected, the
remainder fatigue life may be predicted. The second
technique is sensitive to dislocations on an atomic
level. As dislocation loop length and density begins
to multiple, certain changes are detected in the
velocity and attenuation of the acoustic signal.

Autorentext
Shant Kenderian obtained his BS degree in Production Engineering and Metallurgy from the University of Technology in Baghdad in 1985; MS degree in Manufacturing Engineering and Technology from Cal. State LA in 1996, MS and PhD degrees in Materials Science and Engineering from The Johns Hopkins University in 2002.

Klappentext
Laser generated ultrasound and air-coupled ultrasonic detectors are used to develop an inspection technique for the railroad industry. The Laser Air Hybrid Ultrasonic Technique (LAHUT) has the advantage of performing inspections without establishing contact with or the need to come close to the inspected structures. This feature makes it possible to perform dynamic inspections of tracks from a moving train and stationary wayside inspection of wheels on a passing train. The study considers the most critical flaw types in railroad tracks and wheels. Some are very difficult to detect with currently available technology, others are not possible without a handheld device. The second part of the book uses a contact ultrasonic method to monitor microstructural effects during fatigue cycling of railroad steel. Two experiments configurations are presented. One is very sensitive to microcracks. Once detected, the remainder fatigue life may be predicted. The second technique is sensitive to dislocations on an atomic level. As dislocation loop length and density begins to multiple, certain changes are detected in the velocity and attenuation of the acoustic signal.