Crack Growth Characteristics of Pure Copper for Smart Stress Memory Patch


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A new sensing method called “smart stress memory patch”, which could estimate the maximum stress, the stress amplitude and the fatigue cyclic number simultaneously using Kaiser effect of Acoustic Emission (AE) and crack length of this patch, was developed. In this study, the crack growth characteristics of this patch was evaluated. Pure copper was used for this patch because its good corrosion resistance, stable crack propagation and so on. Two kinds of samples which were rolled and electrodeposited copper were prepared to investigate the effect of microstructure on crack growth behavior. Fatigue test was performed under constant stress amplitude to evaluate the crack growth behavior using the relationship between stress intensity factor range and crack propagation rate. The scattering in fatigue crack growth was also investigated to obtain the relationship between crack length and the fatigue cyclic number including two-sided 95% confidence interval. The effect of thickness and grain size on the scattering was discussed. Finally, good crack growth behavior was obtained and the fatigue cyclic number could be estimated by this patch.



Key Engineering Materials (Volumes 353-358)

Edited by:

Yu Zhou, Shan-Tung Tu and Xishan Xie




S. Nambu and M. Enoki, "Crack Growth Characteristics of Pure Copper for Smart Stress Memory Patch", Key Engineering Materials, Vols. 353-358, pp. 2045-2048, 2007

Online since:

September 2007




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[10] [3] [10] [4] [10] [5] [10] [6] 0. 5 0. 55 0. 6 0. 65 0. 7 0. 75 0. 8 Cyclic number, N Normalized crack length, α 30MPa 40MPa 30MPa 40MPa (a) 95% 95.

[10] [3] [10] [4] [10] [5] [10] [6] 0. 5 0. 55 0. 6 0. 65 0. 7 0. 75 0. 8 Normalized crack length, α Cyclic number, N 30MPa 40MPa 30MPa 40MPa (b) 95% 95% Fig. 4 The relationship between the cyclic number and the normalized crarck length including two-sided 95% confidence interval of (a) rolled Cu with thickness of 0. 2mm and (b) ED Cu.