Plenary and Semi-Plenary Lectures
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| Title: |
| Multi-scale evolution for defect evolution in crystals |
| Lecturer: |
| Wei Yang |
| Abstract: |
| We propose a new multi-scale simulation scheme which seamlessly combines the conventional molecular dynamics (MD) with the continuum mechanics formulated under the material point method (MPM). Examples of high energy Cu-Cu and Si-Si cluster impact are presented. The evolution of displaced atoms is found to depend on the underlying lattice structures. For the case of cluster impact on a beam with pre-existing cracks, the high energy impact may seal the crack with amorphous matters and induces an efflux of atoms ahead of the crack mouth. Large scale simulation based on multi-timestep algorithm are carried out for the interaction of dislocation loops with grain boundaries. The formation and evolution of helix Frank-Read source are revealed for aluminum crystals. |
 Wei Yang got his Ph. D. degree in 1985 at Brown University, with specialization in Solid and Structural Mechanics. Currently, he is a full professor of Engineering Mechanics and the Chairman of the Academic Council of Tsinghua University, Beijing, China, and a member of the Chinese Academy of Sciences. In the same time, he is appointed as the Director for the Office of the National Degree Committee, and oversees all graduate programs in China. He also serves as the Council Member of the China Association of Science and Technology and the President of the Far East and Oceanic Fracture Society. I am the Editor-in-Chief of the international journal Acta Mechanica Sinica and serve on the editorial boards of the Journal of Mechanics and Physics of Solids, International Journal of Solids and Structures, Archive of Applied Mechanics, International Journal of Fracture, International Journal of Damage Mechanics and Fatigue, Fracture of Engineering Materials and Structures. Prof. Yang is the Chairman of Working Party 7 (Micro- and Nano-scale Phenomena in Mechanics) of the International Union of Theoretical and Applied Mechanics. |
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