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Title: Application of nonlinear wave modulation spectroscopy to discern material damage

Application of nonlinear wave modulation spectroscopy to discern material damage Materials containing structural damage have a far greater nonlinear elastic response than materials with no structural damage. This is the basis for nonlinear wave diagnostics of damage, methods which are remarkably sensitive to the detection and progression of damage in materials. Here the authors describe one nonlinear method, the application of harmonics and sum and difference frequency to discern damage in materials. The method is termed Nonlinear Wave Modulation Spectroscopy (NWMS). It consists of exciting a sample with continuous waves of two separate frequencies simultaneously, and inspecting the harmonics of the two waves, and their sum and difference frequencies (sidebands). Undamaged materials are essentially linear in their response to the two waves, while the same material, when damaged, becomes highly nonlinear, manifested by harmonics and sideband generation. The authors illustrate the method by experiments on uncracked and cracked plexiglass and sandstone samples, and by applying it to intact and damaged engine components.
Authors: ; ;
Publication Date:
OSTI Identifier:334312
Report Number(s):LA-UR--99-753; CONF-990505--
ON: DE99002411; TRN: AHC29914%%116
DOE Contract Number:W-7405-ENG-36
Resource Type:Technical Report
Data Type:
Resource Relation:Conference: 2. international conference on emerging technologies in NDT, Athens (Greece), 24-26 May 1999; Other Information: PBD: [1999]
Research Org:Los Alamos National Lab., NM (United States)
Sponsoring Org:USDOE Office of Energy Research, Washington, DC (United States)
Country of Publication:United States
Language:English
Subject: 42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; MATERIALS TESTING; DAMAGE; NONLINEAR PROBLEMS; FREQUENCY ANALYSIS; SPECTROSCOPY; CRACKS; HARMONIC GENERATION; EXPERIMENTAL DATA