2D and 3D mixed-mode elastic-plastic fracture criteria, curvilinear crack growth simulation and FEM code development for airframe materials; funded by AFRL, NASA, NASA/EPSCOR, and SC Space Grant Consortium. Friction stir welding process modeling and simulation; funded by NSF; Metal cutting modeling and analysis; funded by NSF; Superalloy creep, oxygen embrittlement, and damage behavior in elevated temperature applications; funded by AFOSR/DEPSCoR Structural damage detection techniques; funded by NSF/EPSCoR and SC Space Grant Consortium