کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
799736 1467123 2010 18 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Evolution of nanoscale defects to planar cracks in a brittle solid
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی مکانیک
پیش نمایش صفحه اول مقاله
Evolution of nanoscale defects to planar cracks in a brittle solid
چکیده انگلیسی

Fracture of a solid is a highly multiscale process that associates atomic scale bond breaking with macroscopic crack propagation, and the process can be dramatically influenced by the presence of defects in materials. In a nanomaterial, defect formation energy decreases with the reduction of material size, and therefore, the role of defects in crack formation and subsequent crack growth in such materials may not be understood from the classical laws of fracture mechanism. In this study, we investigated the crack formation process of a defective (with missing atoms) nanostructured material (NaCl) using a series of molecular dynamics (MD) simulations. It was demonstrated that simple defects in the form of several missing atoms in the material could develop into a planar crack. Subsequently, MD simulations on failures of nanosized NaCl with pre-defined planar atomistic cracks of two different lengths under prescribed tensile displacement loads were performed. These failure loads were then applied on the equivalent continuum models, separately, to evaluate the associated fracture toughness values using the finite element analysis. For small cracks, the fracture toughness thus obtained is cracksize dependent and the corresponding critical energy release rate is significantly smaller than Griffith’s theoretical value. Explanation for this discrepancy between LEFM and the atomistic model was attempted.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of the Mechanics and Physics of Solids - Volume 58, Issue 7, July 2010, Pages 983–1000
نویسندگان
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