2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 7: Yang Intl. Symp. / Multiscale Material Mechanics
| Editors: | Kongoli F, Aifantis E, Wang H, Zhu T |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 190 pages |
| ISBN: | 978-1-987820-48-5 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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Size effect in nanomaterials
Shaohua Chen1; Yin Yao2;1INSTITUTE OF ADVANCED STRUCTURE TECHNOLOGY, BEIJING INSTITUTE OF TECHNOLOGY, Beijing, China; 2LNM, INSTITUTE OF MECHANICS, CHINESE ACADEMY OF SCIENCES, Beijing, China;
Type of Paper: Regular
Id Paper: 321
Topic: 1
Abstract:
Size effect of nanomaterials is essentially induced by the large ratio of surface to volume. Many experiments have been carried out to explore the size effect in nanomaterials, including characterizing surface atomic structures by using electron diffraction and scanning-probe microscopy. The experimental findings provide a convincing demonstration that size effect plays an important role in the mechanical property of nanomaterials. A typically physical parameter to describe theoretically the surface of nanomaterials is the surface energy density. Within the framework of continuum mechanics, a new theory for nanomaterials based on surface energy density is proposed to predict size effect (surface effect) of nanomaterials. In contrast to previous theories, the linearly elastic constitutive relationship that is usually adopted to describe the surface layer of nanomaterials is not invoked. The surface elastic constants, which is difficult to determine experimentally, are no longer needed in the new theory. Instead, a surface-induced traction to characterize the surface effect in nanomaterials is derived. Only the surface-energy density of bulk materials and the surface-relaxation parameter are needed in the new theory. Both Parameters have clearly physical meanings and are very easy to determine through experiment and simple MD simulation. The new theory is further used to characterize the elastic property of several kinds of nanomaterials or nanostructures, whose predictions agree very well with existing numerical or experimental results. It is demonstrated that the present theory is much convenient for predicting the mechanical behavior of nanomaterials in contrast to the existing ones.