Evaluation of Information Entropy from Acoustic Emission Waveforms as a Fatigue Damage Metric for Al7075-T6


Autoria(s): Sauerbrunn, Christine Marie
Contribuinte(s)

Modarres, Mohammad

Digital Repository at the University of Maryland

University of Maryland (College Park, Md.)

Mechanical Engineering

Data(s)

08/09/2016

08/09/2016

2016

Resumo

Information entropy measured from acoustic emission (AE) waveforms is shown to be an indicator of fatigue damage in a high-strength aluminum alloy. Several tension-tension fatigue experiments were performed with dogbone samples of aluminum alloy, Al7075-T6, a commonly used material in aerospace structures. Unlike previous studies in which fatigue damage is simply measured based on visible crack growth, this work investigated fatigue damage prior to crack initiation through the use of instantaneous elastic modulus degradation. Three methods of measuring the AE information entropy, regarded as a direct measure of microstructural disorder, are proposed and compared with traditional damage-related AE features. Results show that one of the three entropy measurement methods appears to better assess damage than the traditional AE features, while the other two entropies have unique trends that can differentiate between small and large cracks.

Identificador

doi:10.13016/M2ZR5T

http://hdl.handle.net/1903/18743

Idioma(s)

en

Palavras-Chave #Mechanical engineering #Acoustic emission #Aluminum #Fatigue #Information entropy
Tipo

Thesis