NASA/TM-2002-211673 ARL-TR-2725 Evaluation of Fatigue Fracture Properties of Materials John A. Newman U.S. Army Research Laboratory Vehicle Technology Directorate Langley Research Center, Hampton, Virginia Scott C. Forth Langley Research Center, Hampton, Virginia Richard A. Everett, Jr. U.S. Army Research Laboratory Vehicle Technology Directorate Langley Research Center, Hampton, Virginia James C. Newman, Jr. Mississippi State University Mississippi State, Mississippi William M. Kimmel Langley Research Center, Hampton, Virginia Crack Growth and Cryogenic Model May 2002