Measuring and testing – Vibration – By mechanical waves
G01N 2904, G01R 3320
Small changes in material properties of a work piece are detected by measuring small changes in elastic wave velocity and attenuation within a work piece. Active, repeatable source generate coda wave responses from a work piece, where the coda wave responses are temporally displaced. By analyzing progressive relative phase and amplitude changes between the coda wave responses as a function of elapsed time, accurate determinations of velocity and attenuation changes are made. Thus, a small change in velocity occurring within a sample region during the time periods between excitation origin times (herein called "doublets") will produce a relative delay that changes with elapsed time over some portion of the scattered waves. This trend of changing delay is easier to detect than an isolated delay based on a single arrival and provides a direct measure of elastic wave velocity changes arising from changed material properties of the work piece.
patent: 5095465 (1992-03-01), Stokoe II
G. Poupinet et al., "Monitoring Velocity Variations in the Crust Using Earthquake Doublets: An Application to the Calaveras Vault, California," 89 J. Geophys. Res., No. B7, pp. 5719-5731 (July 1984).
Fehler Michael C.
Johnson Paul A.
Phillips W. Scott
Roberts Peter M.
Chilcot Jr. Richard E.
Eklund William A.
Moser William R.
Oen William L.
The United States of America as represented by the United States
Active doublet method for measuring small changes in physical pr does not yet have a rating. At this time, there are no reviews or comments for this patent.If you have personal experience with Active doublet method for measuring small changes in physical pr, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Active doublet method for measuring small changes in physical pr will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-206952