My research interests deal with understanding deformation and fracture processes from the atomic length scale to the macroscopic length scale, especially in materials that exhibit an elastic-plastic constitutive behavior such as ductile metals.

• Brittleness and Ductility of Materials: The goals of this research are twofold: (i) to investigate the fundamental mechanisms at the nano/micro scale around a crack tip that control the macroscopic growth of a crack; and, (ii) to better understand the fundamentals of ductile fracture processes in single crystal materials.
• Measurement of Geometrically Necessary Dislocation Density: The goals of this research are to make a critical set of measurements of the various continuum fields associated with severe deformation states of elastic-plastic single crystals. Using various diffraction and strain measurement techniques, we have determined the crystal lattice rotation associated with various severe deformation states, including at crack tips, around voids and underneath indentations in single crystals. From these measurements, it is possible to determine the geometrically necessary dislocation density which the material must contain.
• Development of analytical solutions for severe deformation states in single crystals: Part of this work has been to derive the stress and velocity fields associated with the growth of a cylindrical void via dislocation mediated plasticity in a single crystal. In addition, we have derived the stress and the form of the deformation fields associated with a Gaussian pressure distribution applied to the surface of a single crystal, such as occurs during laser shock peening of a material.
• Investigation of Laser Shock Processes in Materials: We have developed experimental methods to measure the crystal lattice rotation which occurs due to plastic deformation caused by laser shock peening a single crystal. In addition, microscale x-ray diffraction is utilized to interrogate the residual stress state. Detailed finite element simulations are performed to elucidate further details of the process. This work is in collaboration with Professor Y. Lawrence Yao.
  
• Development of Nanocomposite Thin Films with Enhanced Mechanical Properties: Our group has synthesized various metal matrix thin films which contain nanocomponents, such as alumina and ceria. Mechanical evaluation of the resulting films suggest a significant enhancement of the mechanical properties of the nanocomposite thin films over control thin films of pure metals. This research is in collaboration with Professor Xi Chen.