Research Interest



  1. Multiscale modeling (algorithm and applications)
  2. Mechanics of Energetic materials
  3. Nonlinear mechanics of Nanomaterials and low-dimentional (2D) materials.
  4. Radiation damage, mecahnics of nuclear materials
  5. Ferroelectrics
  6. Glass and amorphous materials.
  7. Polymer and biomaterials

  • Q. Peng*,
    Research Interests
    2D materials, Radiation damage
    Defects, Radiation growth, Radiation damage
    QCDFT, Multiscale modeling, crack, nanoindentation,self-healing materials
    Structures, mechanics, and dynamics of nanostructures

    QCDFT: Quasi-Continuum Density Functional Theory

    Quasi-continuum Density Functional Theory is the first full quantum mechanics simulation of a system at the micron scale and a ground-breaking progress in computational mechanics of materials. This method was first developed by Q. Peng and his collaborators (PRB 78,054118,2008). QDFT is a multiscale approach that is based entirely on density functional theory and allows quantum simulations at the micron scale and beyond. This method combines the coarse graining idea of the adaptive finite element method and the coupling strategy of the quantum mechanics/molecular mechanics (QM/MM) method, and represents a major advance in the quantum simulation of materials properties. It should be stated at the outset that QDFT is not a brute-force electronic structure method, but rather a multiscale approach that can treat large systems - effectively up to billions of electrons. Therefore, some of the electronic degrees of freedom are reduced to continuum degrees of freedom in QDFT. On the other hand, although QDFT utilizes the idea of QM/MM coupling, it does not involve any classical/empirical potentials (or force fields) in the formulation - the energy calculation of QDFT is entirely based on DFT. This is an important feature and advantage of QDFT, which qualifies it as a bona fide quantum simulation method. The method was verified by a multitude of tests, including nano- indentation of an Al thin film. (More)

    Localization of Stress Relaxation
    in Amorphous Materials

    Structural relaxation events in atomic glasses are well known to be highly localized, whereas in polymer systems, they are likely to be of a more diffuse nature. The present project, which is still in an initial stage, aims at clarifying the role of molecular on the spatial correlation of stress relaxation events.

    Ferroelectrics

    Research in computer simulations of Ferroelectrics using first principle and molecular dynamics methods.

    Optics

    Near field diffraction of short pulse laser and quantum beat. Study the dispersion of wavelengthdivision multiplexing (WDM) in fiber-optics communications.

     

    Dense suspension flow

    Research on the dense suspension flow on inhomogeneous surface for under-fill flip-chip electronics packing. Study capillary flow of
    dense suspensions, in particular commercial underfill encapsulant on different surfaces, including measuring wetting angles and viscosities. Such flow on mixed
    surfaced was examined in terms of the Washburn model.