Heterogeneity in deformation of granular ceramics under dynamic loading

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• 作者：J.Y. Huang^a ; ^b ; ^c ; L. Lu^a ; ^c ; D. Fan^c ; T. Sun^d ; K. Fezzaa^d ; S.L. Xu^a ; ^{slxu99@ustc.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; M.H. Zhu^b ; ^{zhuminghao@swjtu.cn" class="auth_mail" title="E-mail the corresponding author} ; S.N. Luo^c ; ^b ; ^{sluo@pims.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Powder processing ; Dynamic compaction ; X-ray imaging ; Digital image correlation ; Heterogeneous deformation
• 刊名：Scripta Materialia
• 出版年：2016
• 出版时间：15 January 2016
• 年：2016
• 卷：111
• 期：Complete
• 页码：114-118
• 全文大小：1445 K

文摘

Dynamic compression experiments are conducted on micron-sized SiC powders of different initial densities with a split Hopkinson pressure bar. Digital image correlation is applied to images from high-speed X-ray phase contrast imaging to map dynamic strain fields. The X-ray imaging and strain field mapping demonstrate the degree of heterogeneity in deformation depends on the initial powder density; mesoscale strain field evolution is consistent with softening or hardening manifested by bulk-scale loading curves. Statistical analysis of the strain probability distributions exhibits exponential decay tail similar to those of contact forces, which are supposed to lead to the grain-scale heterogeneity of granular materials.