Crack Growth Characteristics of Pure Copper for Smart Stress Memory Patch
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.
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