Dr. W. Steve Johnson
steve.johnson@mse.gatech.edu
Love
166
US
Office: (404) 894-3013
Fax: (404) 894-9140
Instructor informationEducation
Ph.D., Duke University, 1979
M.S., Virginia Polytechnic Institute and State University, 1975
B.S., Virginia Polytechnic Institute and State University, 1971
Research Area and Descriptors
Mechanics of Materials
Fatigue, fracture mechanics, and durability of materials and structures
Background
Dr. Johnson has twenty-seven years of experience studying failure mechanisms in a wide range of material systems for aeronautical, space, and naval applications. He has pioneered several life predictive methodologies for metallic, bonded structures and metal matrix composites. From 1979 until he joined Georgia Tech in June 1994, Dr. Johnson was employed at the National Aeronautics and Space Administration (NASA) Langley Research Center as a Senior Scientist. He led several research teams during that period. In his last four years at NASA, he led the Material Durability Program for the High-Speed Civil Transport and served as principal investigator for developing life-prediction methodologies to be employed on the National AeroSpace Plane. These programs were charged with developing life-predictive methodologies and assessing the long-term durability of materials to be used on these very advanced aircraft.
Research
Dr. Johnsons current research is directed toward studying the durability of many advanced material systems used in extreme environments. His sponsors include the National Aeronautics and Space Administration, Lockheed-Martin Corporation, the National Science Foundation, the U. S. Air Force, the Federal Aviation Administration, and the Office of Naval Research. His research deals with both metal and polymer matrix composite materials, aluminums, titaniums, hybrid titanium composite laminates, and both bonded and bolted joints. Much of the research deals with high-temperature testing and advanced damage modeling, which includes fatigue and fracture analysis that incorporates induced thermal stresses, thermo-viscoplasticity, oxidation and general material degradation with time. Much of this research is in support of high-profile national programs such as the F-22 stealth fighter and the futuristic High-Speed Civil Transport.
Distinctions
o American Society of Mechanical Engineers Fellow, 2004
o National Aeronautics and Space Administration Aerospace Technology, Advanced Space Transportation Subcommittee, 2002-present
o American Society of Materials International Fellow, 2002
o American Society for Testing and Materials Fellow, 1997
o Georgia Institute of Technology Composites Education and Research Center Director, 1996-present
o Journal of Composites Technology and Research Editor-in Chief, 1990-2001
Representative Publications
S. Sacks and W. S. Johnson. 1998. Effects of Thermal Aging on the Mechanical Behavior of K-3B Matrix Material. Journal of Thermoplastic Composite Materials 11, 1-14.
E. Li and W. S. Johnson. 1998. Fatigue of Unnotched Hybrid Titanium Composite Laminates. Journal of Composite Technology and Research 20(1), 3-12.
R. W. Hamm and W. S. Johnson. 1998. Survey of the State of the Art in Small Crack Research. Journal of Testing and Evaluation 26(3), 168-175.
R. V. Valentin, L. M. Butkus, and W. S. Johnson. 1998. A Finite Element and Experimental Evaluation of Boron-Epoxy Doublers Bonded to an Aluminum Substrate. Journal of Composites Technology and Research 20(2), 108-119.
W. S. Johnson and J. R. Calcaterra. 1998. A Fiber Stress Based Model for Thermomechanical Fatigue Life Predictions of Titanium Matrix Composites. International Journal of Fatigue and Fracture of Engineering Materials and Structures 21, 479-492. |