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Date
2019-07-14
Journal Title
Journal ISSN
Volume Title
Publisher
ASME
Abstract
ABSTRACT
When inspection is required to be conducted from
a remote distance, due for example to safety concerns,
guided ultrasonic wave testing technique is the
preferred choice. Guided waves are usually low
frequency hence are not subjected to much attenuation
relative to the bulk waves. As a result, guided waves
can travel a longer distance. One of the limitations of
guided waves however, is that the low frequency
(longer wavelength) used lead to lower resolution
capabilities due to the inherent diffraction limits of λ/2
(where λ is wavelength). Guided waves are therefore
generally used as screening tools to locate areas of
interest. A higher resolution technique is then
employed to further investigate and characterize the
features of defects in the identified areas.
To overcome this challenge of resolution, a
technique is proposed that increases the resolution
capability of guided waves beyond the diffraction
limit. Simulation using commercial finite element
software is used to optimize variables involved in the
proposed method. The simulation is then validated
with experiments. In the present work a resolution of
λ/72 is demonstrated experimentally.
Description
Keywords
Keywords: guided waves, super resolution, metamaterials