Aug. 2000 – Present Professor, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University. Aug. 1996 – July 2000 Associate Professor, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University. Aug. 1992 – July 1996 Assistant Professor, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University. Aug. 1989 – July 1992 Research Scientist, Department of Mechanical Engineering, Virginia Polytechnic Institute and State University. Sept. 1987 ‑ July 1989 Senior Engineer: Aerostructures, Inc., USA. The work involved: Finite Element Modeling and stress analysis of aircraft components using PATRAN and NASTRAN computer codes; fatigue damage and crack propagation studies; vibration analysis of aircraft subjected to shock loads. Sept. 1986 ‑ Aug. 1987 Visiting Assistant Professor, Dept. of Aerospace and Ocean Engineering, Virginia Polytechnic Institute and State University. Jan. 1983 ‑ June 1986 Research Assistant, Dept. of Engineering Science and Mechanics, Virginia Polytechnic Institute and State University. March 1981 ‑ Dec. 1982 Instructor in the School of Engineering of the National University of Cordoba, Argentina. Feb. 1981 ‑ Feb. 1982 Junior Engineer: Structural Mechanics Group, National University of Cordoba‑ Atomic Energy Commission for seismic evaluation of Embalse Nuclear Power Plant, Argentina.