Estimation of fatigue life using electromechanical impedance technique

Yee Yan Lim; Chee Kiong Soh

doi:10.1117/12.846902

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31 March 2010 Estimation of fatigue life using electromechanical impedance technique

Yee Yan Lim, Chee Kiong Soh

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Proceedings Volume 7647, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2010; 764722 (2010) https://doi.org/10.1117/12.846902
Event: SPIE Smart Structures and Materials + Nondestructive Evaluation and Health Monitoring, 2010, San Diego, California, United States

Abstract

Fatigue induced damage is often progressive and gradual in nature. Structures subjected to large number of fatigue load cycles will encounter the process of progressive crack initiation, propagation and finally fracture. Monitoring of structural health, especially for the critical components, is therefore essential for early detection of potential harmful crack. Recent advent of smart materials such as piezo-impedance transducer adopting the electromechanical impedance (EMI) technique and wave propagation technique are well proven to be effective in incipient damage detection and characterization. Exceptional advantages such as autonomous, real-time and online, remote monitoring may provide a cost-effective alternative to the conventional structural health monitoring (SHM) techniques. In this study, the main focus is to investigate the feasibility of characterizing a propagating fatigue crack in a structure using the EMI technique as well as estimating its remaining fatigue life using the linear elastic fracture mechanics (LEFM) approach. Uniaxial cyclic tensile load is applied on a lab-sized aluminum beam up to failure. Progressive shift in admittance signatures measured by the piezo-impedance transducer (PZT patch) corresponding to increase of loading cycles reflects effectiveness of the EMI technique in tracing the process of fatigue damage progression. With the use of LEFM, prediction of the remaining life of the structure at different cycles of loading is possible.

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Yee Yan Lim and Chee Kiong Soh "Estimation of fatigue life using electromechanical impedance technique", Proc. SPIE 7647, Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2010, 764722 (31 March 2010); https://doi.org/10.1117/12.846902

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