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Title: Method and apparatus for determining material structural integrity

Abstract

Disclosed are a nondestructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis to determine the damping loss factor. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity vs time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method: if an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the coil current. If a reciprocating transducer is used, the vibrational force is determined by a force gauge in the transducer. Using vibrational analysis, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity data. Damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.

Inventors:
Issue Date:
Research Org.:
Westinghouse Savannah River Co., Aiken, SC (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
206402
Patent Number(s):
-US-A8194432
Application Number:
ON: DE96006454; PAN: 8-194,432
Assignee:
Dept. of Energy SRS; SCA: 440800; 420500; PA: EDB-96:061147; NTS-96:011877; SN: 96001550305
DOE Contract Number:  
AC09-89SR18035
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 1994
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; BUILDING MATERIALS; DEFECTS; ACOUSTIC TESTING; MECHANICAL VIBRATIONS; DAMPING; NONDESTRUCTIVE TESTING

Citation Formats

Pechersky, M.J. Method and apparatus for determining material structural integrity. United States: N. p., 1994. Web.
Pechersky, M.J. Method and apparatus for determining material structural integrity. United States.
Pechersky, M.J. Sat . "Method and apparatus for determining material structural integrity". United States. https://www.osti.gov/servlets/purl/206402.
@article{osti_206402,
title = {Method and apparatus for determining material structural integrity},
author = {Pechersky, M.J.},
abstractNote = {Disclosed are a nondestructive method and apparatus for determining the structural integrity of materials by combining laser vibrometry with damping analysis to determine the damping loss factor. The method comprises the steps of vibrating the area being tested over a known frequency range and measuring vibrational force and velocity vs time over the known frequency range. Vibrational velocity is preferably measured by a laser vibrometer. Measurement of the vibrational force depends on the vibration method: if an electromagnetic coil is used to vibrate a magnet secured to the area being tested, then the vibrational force is determined by the coil current. If a reciprocating transducer is used, the vibrational force is determined by a force gauge in the transducer. Using vibrational analysis, a plot of the drive point mobility of the material over the preselected frequency range is generated from the vibrational force and velocity data. Damping loss factor is derived from a plot of the drive point mobility over the preselected frequency range using the resonance dwell method and compared with a reference damping loss factor for structural integrity evaluation.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1994},
month = {1}
}