1. A new ultrasonic technique for detection and sizing of small cracks in studs and bolts
- Author
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Dong M. Suh and Whan Woo Kim
- Subjects
Engineering ,business.product_category ,business.industry ,Fissure ,Mechanical Engineering ,Structural engineering ,Fastener ,Sizing ,symbols.namesake ,medicine.anatomical_structure ,Mechanics of Materials ,Nondestructive testing ,Bolted joint ,Solid mechanics ,medicine ,symbols ,Ultrasonic sensor ,Rayleigh wave ,business - Abstract
If small cracks in stud bolts are not detected early enough, they can grow rapidly and cause catastrophic disasters in industrial facilities such as nuclear power plants. Their detection, despite its importance, is known to be a very difficult problem due to the complicated structures of the stud bolts. This study shows a method of detecting the existence and determining the size of a small crack in a root between two crests in the bolt threads using ultrasound. The Rayleigh wave propagating from the tip of a crack to the opening of the same crack is utilized. A delayed pulse, due to the Rayleigh wave, is detected between regularly spaced pulses from the threads, with the delay time being proportional to the size of the crack. Theoretical explanation is presented and experimental results demonstrating detection of cracks as small as 0.5 mm are shown.
- Published
- 1995
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