Hyper-QC: An accelerated finite-temperature quasicontinuum method using hyperdynamics |
| |
| Institution: | 1. Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, MN 55455, USA;2. School of Mathematics, University of Minnesota, Minneapolis, MN 55455, USA;3. Los Alamos National Laboratory, Theoretical Division T-1, Los Alamos, NM, USA;1. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China;2. University of Chinese Academy of Sciences, Beijing 100049, China;1. Section for Materials Science and Advanced Characterization, Department of Wind Energy, Technical University of Denmark, Risø Campus, Roskilde, DK-4000, Denmark;2. Materials Science & Technology Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN, 37830, USA;1. School of Civil Engineering, Harbin Institute of Technology, Harbin, 150090, China;2. Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, Harbin Institute of Technology, Harbin, 150090, China;3. Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology, Harbin Institute of Technology, Harbin, 150090, China |
| |
| Abstract: | The quasicontinuum (QC) method is a spatial multiscale method that extends the length scales accessible to fully atomistic simulations (like molecular dynamics (MD)) by several orders of magnitude. While the recent development of the so-called “hot-QC method” enables dynamic simulations at finite temperature, the times accessible to these simulations remain limited to the sub-microsecond time scale due to the small time step required for stability of the numerical integration. To address this limitation, we develop a novel finite-temperature QC method that can treat much longer time scales by coupling the hot-QC method with hyperdynamics—a method for accelerating time in MD simulations. We refer to the new approach as “hyper-QC”. As in the original hyperdynamics method, hyper-QC is targeted at dynamical systems that exhibit a separation of time scales between short atomic vibration periods and long waiting times in metastable states. Acceleration is achieved by modifying the hot-QC potential energy to reduce the energy barriers between metastable states in a manner that ensures that the characteristic dynamics of the system are preserved. First, the high accuracy of hot-QC in reproducing rare event kinetics is demonstrated. Then, the hyper-QC methodology is validated by comparing hyper-QC results with those of hot-QC and full MD for a one-dimensional chain of atoms interacting via a Lennard–Jones potential. |
| |
| Keywords: | Fracture Constitutive behavior Finite elements Probability and statistics Multiscale methods |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
