1 / 13

Strategies for Multiscale Modelling

Strategies for Multiscale Modelling. Dimitri Vvedensky The Blackett Laboratory, Imperial College, London, UK. DDV, J. Phys.: Condens. Matter 16 , R1537–R1576 (2004). Outline. What is multiscale modelling? (cf. Russ’s talk) Why multiscale modelling?

skylar
Download Presentation

Strategies for Multiscale Modelling

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Strategies for Multiscale Modelling Dimitri Vvedensky The Blackett Laboratory, Imperial College, London, UK DDV, J. Phys.: Condens. Matter16, R1537–R1576 (2004)

  2. Outline • What is multiscale modelling? (cf. Russ’s talk) • Why multiscale modelling? • Methods for multiscale modelling • Coarse graining as a unifying theme • Outstanding issues

  3. Why Multiscale Modelling? • Existence of fundamentally multiscale phenomena Crack initiation and propagation • Materials design Atoms to engineering • Nanostructures Nanotubes, etc New physical effects New device concepts • Biological applications Tissue engineering Interaction between H2O and biological surfaces Implants • Availability of computational power

  4. Nanotube with Gd–Metallofullerenes K. Suenaga et al., Science290, 2280 (2000) 3 nm

  5. Deformation of Carbon Nanotubes Yakobson et al., Phys. Rev. Lett.76, 2511 (1996) • axial compression • Tersoff–Brenner potential

  6. Multiscale Processes in Medical Implants B. Kasemo, Surf. Sci.500, 656 (2002) Time scale ns µs ms

  7. Moore’s Law Source: www.intel.com

  8. Methods for Multiscale Modelling • Sequential Methods • Separation of length and time scales • Parameter passing, KMC • Speakers: Kratzer • Concurrent Methods • Different length and time scales within hybrid scheme • Typically DFT, MD, continuum (FE); Level set • Speakers: Vashishta, Kaxiras, Ortiz, Ratsch • Coarse Graining • Integration over fast time scales short length scales • Speakers: Rudd, DDV, Plechac

  9. Molecular Dynamics–Finite Element Hybrid E. Lidikoris et al., Phys. Rev. Lett.87, 086104 (2001)

  10. Basic Coarse Graining

  11. Coarse-Graining Calculations • Free energies for equilibrium systems • Effective Langevin equations for nonequilibrium systems • Scaling regimes • Spatially–varying coarse graining

  12. Quasicontinuum Method R. E. Miller and E. B. Tadmor, J. Comput-Aided Mater.9, 203 (2002)

  13. Outstanding issues • Exchange–correlation potentials for DFT • Potentials for MD • Simulations at finite temperatures • Time scales accessible by molecular dynamics • Mode transmission across atomistic/continuum interfaces • Error estimation

More Related