Conventional non-destructive evaluation (NDE) methods are not very effective in monitoring the material conditions of advanced composite and adhesive joints. A technology that has been proposed to enhance the inspectability of advanced composites is the particle tagging technique. Two theoretical models were recently proposed to characterize the dynamic behavior of ferromagnetic and magnetostrictive tagging particles. These theoretical models concerning the development of an active tagging

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... ique with embedded ferromagnetic and magnetostrictive particles and magnetic excitation are now experimentally verified. The experimental results of the active particle tagging shows a variation in the dynamic response of the specimens when defects and/or damage are presents. The sensory signature from a tagged polymer is extracted as a result of tl1e interaction between the embedded particles and their host matrix. A study of various types of composites and tagging particles for passive and active tagging was performed. Experimental validation of concepts for tagging of structural materials for on-site inspection prior to installation have also been explored. The on-site particle tagging inspection has been verified on laboratory specimens obtained from industry and was shown to be very efficient. Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.