کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
279365 1430368 2007 25 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Modelling the evolution of dislocation structures upon stress reversal
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی عمران و سازه
پیش نمایش صفحه اول مقاله
Modelling the evolution of dislocation structures upon stress reversal
چکیده انگلیسی

The non-uniform distribution of dislocations in metals causes a material anisotropy that manifests itself through strain path dependency of the mechanical response. This paper focuses on the micromechanical modelling of FCC metals with a dislocation cell structure. The objective is to enhance the continuum cell structure model, developed in Viatkina et al. [Viatkina, E., Brekelmans, W., Geers, M., submitted for publication. Modelling of the internal stress in dislocation cell structures], with an improved description of the dislocation density evolution enabling a correct prediction of strain path change effects under complete or partial stress reversal. Therefore, attention is concentrated on the dislocation mechanisms accompanying a stress reversal. Physically based evolution equations for the local density of the statistically stored dislocations are formulated to describe the formation and dissolution of a dislocation structure under deformation. Incorporation of these equations in the cell structure model results in improved predictions for the effects of large strain path changes. The simulation results show a good agreement with experimental data, including the well-known Bauschinger effect. The contributions of the dislocation mechanisms and the internal stresses to the resulting macroscopic strain path change effects are analysed. The dislocation dissolution is concluded to have a significant influence on the macroscopic behaviour of FCC metals after stress reversals.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Solids and Structures - Volume 44, Issues 18–19, September 2007, Pages 6030–6054
نویسندگان
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