Dynamic recrystallisation of ice aggregates during co-axial viscoplastic deformation: a numerical approach

• Published in: Journal of Glaciology
• Main Authors: Llorens Verde, Maria Gema, Griera, Albert, Bons, Paul D., Roessiger, Jens, Lebensohn, Ricardo, Evans, Lynn, Weikusat, Ilka
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: INT GLACIOL SOC 2016
• Subjects: Journal of Glaciology
• Online Access: https://epic.awi.de/id/eprint/41232/; https://epic.awi.de/id/eprint/41232/1/Llorens2016.pdf; http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10354953&fileId=S0022143016000289; https://hdl.handle.net/10013/epic.48314; https://hdl.handle.net/10013/epic.48314.d001

Results of numerical simulations of co-axial deformation of pure ice up to high-strain, combining full-field modelling with recrystallisation are presented. Grain size and lattice preferred orientation analysis and comparisons between simulations at different strain-rates show how recrystallisation has a major effect on the microstructure, developing larger and equi-dimensional grains, but a relatively minor effect on the development of a preferred orientation of c-axes. Although c-axis distributions do not vary much, recrystallisation appears to have a distinct effect on the relative activities of slip systems, activating the pyramidal slip system and affecting the distribution of a-axes. The simulations reveal that the survival probability of individual grains is strongly related to the initial grain size, but only weakly dependent on hard or soft orientations with respect to the flow field. Dynamic recrystallisation reduces initial hardening, which is followed by a steady state characteristic of pure-shear deformation.