On the conditions of strain localization and microstructure fragmentation under high-rate loading

Autor: M. P. Bondar, Andrey I. Dmitriev, Sergey G. Psakhie, A. Yu. Nikonov
Rok vydání: 2013
Předmět:
Zdroj: Physical Mesomechanics. 16:191-199
ISSN: 1990-5424
1029-9599
DOI: 10.1134/s1029959913030028
Popis: The paper reports on research in the deformation and fragmentation mechanisms of coarse- and fine-grained materials under high-rate loading. The study was performed by an experimental procedure based on collapse of thick-walled hollow cylinders and by molecular dynamics simulation. The key issue was to study the formation of plastic strain localization bands. It is found that the pattern of plastic deformation is governed by loading conditions and characteristic grain sizes. For a coarse-grained material, the governing mechanism is dislocation deformation resulting in localization bands. For a fine-grained material, the governing mechanism is grain boundary sliding with attendant fragmentation of the material. A dependence of the strain rate and degree on the critical grain size was disclosed. The computer simulation revealed mechanisms of grain boundary sliding on the scales studied.
Databáze: OpenAIRE
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