Molecular dynamics simulation of fatigue damage in metals
Lunt, William S.
MetadataShow full item record
Molecular dynamics simulation was conducted to better understand the mechanism of fatigue failure and to identify a parameter(s) that can indicated progressive damage due to cyclic loading. The Embedded Atom Method (EAM) was used for copper atoms subjected to cyclic loadings. Defective crystal structures including vacancies or impurities were considered for the study. The results showed that there was an increase in potential energy and kinetic energy, respectively, in the metal as the number of cycles increased. This means the metal becomes weaker, i.e., an indication of progressive damage. Therefore, the change of potential energy may be used as an indicator for fatigue damage accumulation. Furthermore, the relative distances between vacancies (or impurities) increased globally with fluctuation as the number of loading-unloading cycles increased.
Approved for public release; Distribution is unlimited
Showing items related by title, author, creator and subject.
The effects of reversing sleep-wake cycles on sleep and fatigue on the crew of USS John C. Stennis Nguyen, John Loc (Monterey, California. Naval Postgraduate School, 2002-09);This study explores the effects of reversing the work-sleep schedules of the crew aboard the USS JOHN C. STENNIS. It also reviews current research in the field of sleep deprivation and the resultant performance decrements ...
Effects of sleep deprivation on U.S. Navy watchstander performance onboard the independence class Littoral Combat Ship (LCS- 2) Davey, James D. (Monterey, California: Naval Postgraduate School, 2013-09);In spite of the incredible technologic advances over the history of the U.S. Navy, the human operator continues to be the most important part of any system. The Littoral Combat Ship (LCS) concept proposed to reduce the ...
Walter, Richard W. (Monterey, California. Naval Postgraduate School, 1992-09);NAVAIR utilizes the fatigue spectrum of an existing Navy aircraft to set the structural design requirements for a new Navy aircraft. The current design requirement is for the new aircraft to withstand a fatigue spectrum ...