Abstract
The loading effect induced by the contact between a parabolic duralumin tip and a free glass plate is investigated using Lamb waves and an optical heterodyne interferometric probe. The instrument detects 1-MHz impulse symmetric S₀ and antisymmetric A₀ Lamb wave trains launched in 1-mm-thick B270-type glass. Strain-optic modeling is carried out to explain optical measurement through the transparent medium and the loading effect of the tip. Three-wave optical interference modeling is also developed to explain the presence of fringes of equal thickness in C-scans of both modes propagating in a plate that has a 1.1-mrad wedge. Results show that through-glass probing inverts by a factor of -3.1 the signal that is normally returned by the interferometer at a free-air surface for the S₀ Lamb mode. Fringes of equal thickness reveal the spatial extension of the mechanical loading. Through-glass probing on A₀ produces about the same signal as in a free-air measurement configuration. This mode appears to be more appropriate for the evaluation of the loading effect of the tip. For this parabolic tip, we observe an A₀ attenuation of about 50% in the contact area.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
