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Use of Acoustic Emission to Monitor Progressive Damage Accumulation in Kevlar (R) 49 CompositesAcoustic emission (AE) data acquired during intermittent load hold tensile testing of epoxy impregnated Kevlar(Registeres TradeMark) 49 (K/Ep) composite strands were analyzed to monitor progressive damage during the approach to tensile failure. Insight into the progressive damage of K/Ep strands was gained by monitoring AE event rate and energy. Source location based on energy attenuation and arrival time data was used to discern between significant AE attributable to microstructural damage and spurious AE attributable to noise. One of the significant findings was the observation of increasing violation of the Kaiser effect (Felicity ratio < 1.0) with damage accumulation. The efficacy of three different intermittent load hold stress schedules that allowed the Felicity ratio to be determined analytically is discussed.
Document ID
20090026552
Document Type
Conference Paper
Authors
Waller, Jess M. (NASA White Sands Test Facility NM, United States)
Saulsberry, Regor L. (NASA White Sands Test Facility NM, United States)
Andrade, Eduardo (Texas Univ. El Paso, TX, United States)
Date Acquired
August 24, 2013
Publication Date
July 26, 2009
Subject Category
Composite Materials
Report/Patent Number
JSC-CN-18563
Meeting Information
Quantiative Nondestructive Evaluation (QNDE) 2009(Kingston, RI)
Distribution Limits
Public
Copyright
Public Use Permitted.

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