Localisation of plastic deformation in stretching plates: microstructure effects

Abstract

The incidence of microstructural characteristics on the localization of plastic deformation in stretching plates in the form of necking was investigated by performing polycrystal plasticity simulations: crystal aggregates were generated by a Voronoї tessellation algorithm and crystal orientations were randomly distributed among the grains. The most outstanding results of this analysis, detailed in [1], are presented here. During dynamic extension, a transition is displayed between an initial grain scale strain organization towards the development of much larger patterns and a final stage during which one or a few localization zones develop drastically. The influence of the initial strain distribution on the final necking framework is enhanced when the number of grains in the plate thickness is reduced or the loading rate is moderate. Additionally, the sensitivity of the different stages of the localization process to texture has been highlighted: the co-existence of both favorably and unfavorably oriented grains raises the initial strain heterogeneity and triggers macroscopic localization at shorter times.

Abstract

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