Ongoing efforts to develop traction-separation laws for continuum models based on atomistic simulations
Event details
| Date | 28.03.2019 |
| Hour | 16:00 › 17:00 |
| Speaker | Dr. Rebecca Janisch is Research Group Leader in the field of Mechanical Properties of Interfaces, at the Department of Micromechanical and Macroscopic Modeling at ICAMS, Ruhr-Universität Bochum, Germany. Her work mostly focuses on understanding mechanical properties of interfaces using both Ab-initio electronic structure calculations, and classical molecular dynamics simulations. Dr. Janisch obtained her PhD at the department “Gefüge und Grenzflächen”, Max PlanckInstitut für Metallforschung Stuttgart. She held postdoctoral research positions at the Technische Universität Chemnitz in Germany, and at the University of California Santa Barbara, USA. Prior to joining Ruhr-Universität Bochum, Dr. Janisch was Member of academic staff at the Universität Erlangen-Nürnberg in Germany. |
| Location | |
| Category | Conferences - Seminars |
Abstract: Continuum mechanics provides an efficient way to model fracture at the engineering scale, based on stresses, stress intensity factors, and energy release rates. Additionally, material-specific information and failure criteria are required to describe fracture at this scale. At the atomic scale, in contrast, the breaking of atomic bonds is caused by critical forces acting on individual atoms. Approaches to bridge the two scales so far suffer from the impossibility to directly convert the atomic forces at which bonds are breaking into meaningful continuum mechanical failure stresses.
Challenges on the way are the environment-dependency of the critical forces, which are needed to separate pairs of atoms, as well as the quantitative difference between critical stresses on the atomistic respectively mesoscopic length scale by several orders of magnitude. In this presentation existing approaches to overcome these problems will be reviewed. Our ongoing efforts to develop a fracture mechanical model will be presented, which scales the atomic forces occurring during bond breaking into meaningful continuum mechanical quantities in form of scale-sensitive traction separation laws. The model is established for fracture in brittle, single crystalline tungsten. Possible extensions to systems including defects such as grain boundaries, will be discussed.
Challenges on the way are the environment-dependency of the critical forces, which are needed to separate pairs of atoms, as well as the quantitative difference between critical stresses on the atomistic respectively mesoscopic length scale by several orders of magnitude. In this presentation existing approaches to overcome these problems will be reviewed. Our ongoing efforts to develop a fracture mechanical model will be presented, which scales the atomic forces occurring during bond breaking into meaningful continuum mechanical quantities in form of scale-sensitive traction separation laws. The model is established for fracture in brittle, single crystalline tungsten. Possible extensions to systems including defects such as grain boundaries, will be discussed.
Practical information
- Informed public
- Free
Organizer
- LAMMM
Contact
- Géraldine Palaj