1. National Institute of Aerospace, Hampton, VA 23666-6147 US.
2. Resident Research Scientist, Durability, Damage Tolerance and Reliability Branch, NASA Langley Research Center, Hampton, VA 23681-2199 US.
3. Science and Technology Corporation, Hampton, VA 23666-6413 US.
4. NASA Langley Research Center, Hampton, VA 23681-2199 US.
5. NASA Langley Research Center, Hampton, VA 23681-2199 US (Corresponding author), e-mail: stephen.w.smith@nasa.gov