The fatigue limit diagram shows the allowable stress zone for constant amplitude fatigue loading. It was shown is this study that fretting fatigue failure occured in the case of variable amplitude loading condition even when every stress amplitude was kept below the fretting fatigue limit diagram. The reason why such a phenomenon occurred was examined using repeated two-step loading fretting fatigue test. The first step stress of the repeated two-step loading was chosen as R= -1 and the second step stress was with high mean stress. A non-propagating crack was formed by the first step stress even well below the fatigue limit. This crack functioned as a pre-crack for the second step stress with high mean stress. Consequently, fatigue failure did occur even when every stress was kept below the fretting fatigue limit diagram of constant amplitude. The fatigue limit diagram does not necessarily guarantee the safety in the case of variable amplitude loading.
|Number of pages||6|
|Journal||Nihon Kikai Gakkai Ronbunshu, A Hen/Transactions of the Japan Society of Mechanical Engineers, Part A|
|Publication status||Published - May 2005|
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering