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Title: High energy, low frequency, ultrasonic transducer

Abstract

A wide bandwidth, ultrasonic transducer to generate nondispersive, extensional, pulsed acoustic pressure waves into concrete reinforced rods and tendons. The wave propagation distance is limited to double the length of the rod. The transducer acoustic impedance is matched to the rod impedance for maximum transfer of acoustic energy. The efficiency of the transducer is approximately 60 percent, depending upon the type of active elements used in the transducer. The transducer input energy is, for example, approximately 1 mJ. Ultrasonic reflections will occur at points along the rod where there are changes of one percent of a wavelength in the rod diameter. A reduction in the rod diameter will reflect a phase reversed echo, as compared with the reflection from an incremental increase in diameter. Echo signal processing of the stored waveform permits a reconstruction of those echoes into an image of the rod. The ultrasonic transducer has use in the acoustic inspection of long (40+foot) architectural reinforcements and structural supporting members, such as in bridges and dams.

Inventors:
 [1]
  1. (Hayward, CA)
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
873185
Patent Number(s):
6109109
Assignee:
Regents of University of California (Oakland, CA) LLNL
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
energy; frequency; ultrasonic; transducer; wide; bandwidth; generate; nondispersive; extensional; pulsed; acoustic; pressure; waves; concrete; reinforced; rods; tendons; wave; propagation; distance; limited; double; length; rod; impedance; matched; maximum; transfer; efficiency; approximately; 60; percent; depending; type; active; elements; input; example; mj; reflections; occur; changes; wavelength; diameter; reduction; reflect; phase; reversed; echo; compared; reflection; incremental; increase; signal; processing; stored; waveform; permits; reconstruction; echoes; image; inspection; 40; foot; architectural; reinforcements; structural; supporting; bridges; dams; wide band; acoustic pressure; wave propagation; pressure waves; structural support; acoustic impedance; signal processing; ultrasonic transducer; acoustic energy; active element; pressure wave; active elements; input energy; propagation distance; signal process; wide bandwidth; /73/367/

Citation Formats

Brown, Albert E. High energy, low frequency, ultrasonic transducer. United States: N. p., 2000. Web.
Brown, Albert E. High energy, low frequency, ultrasonic transducer. United States.
Brown, Albert E. Sat . "High energy, low frequency, ultrasonic transducer". United States. https://www.osti.gov/servlets/purl/873185.
@article{osti_873185,
title = {High energy, low frequency, ultrasonic transducer},
author = {Brown, Albert E.},
abstractNote = {A wide bandwidth, ultrasonic transducer to generate nondispersive, extensional, pulsed acoustic pressure waves into concrete reinforced rods and tendons. The wave propagation distance is limited to double the length of the rod. The transducer acoustic impedance is matched to the rod impedance for maximum transfer of acoustic energy. The efficiency of the transducer is approximately 60 percent, depending upon the type of active elements used in the transducer. The transducer input energy is, for example, approximately 1 mJ. Ultrasonic reflections will occur at points along the rod where there are changes of one percent of a wavelength in the rod diameter. A reduction in the rod diameter will reflect a phase reversed echo, as compared with the reflection from an incremental increase in diameter. Echo signal processing of the stored waveform permits a reconstruction of those echoes into an image of the rod. The ultrasonic transducer has use in the acoustic inspection of long (40+foot) architectural reinforcements and structural supporting members, such as in bridges and dams.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}

Patent:

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