Localized strain evolution and accumulation at the notch tip of an aluminum single crystal under cyclic loading

Abstract

A synchronized analysis of strain localization and slip system interaction, with full‐field strain mapping, in the vicinity of a notch tip in aluminum single crystal is presented. Progressive strain accumulation, prominently along one of the slip shear bands, was demonstrated quantitatively under cyclic loading, using digital image correlation. This dominant slip band potentially critical for the nucleation and growth of a crack. Also, triple slip active regions found on the surface indicate the participation of all three in‐plane slip systems. Therefore, the use of either diagonal or weakly coupled hardening rule is recommended even in aluminum single crystals, instead of the commonly used isotropic models. Finally, the results from this work provide quantitative data on the progressive strain accumulation and localization around a notch under cyclic loading that can be used in model validation for single and polycrystal plasticity.

Low Cycle Fatigue and Damage Evaluation on 16MnCr5 Alloy Steel

“…It is known that persistent slip bands promote the formation of microplasticity areas and the emergence of microcracks; this has been reported previously elsewhere. [ 46 ] The observed surface corresponding to cyclic strain amplitude of 0.004 (Figure 9d) reveals the presence of grain boundaries. This grain boundary revealing process had been associated with a dislocation interaction, which produced the strain localization at the grain boundaries.…”