A LIFING PROCEDURE TO PREDICT LIFE FOR SHOT-PEENED CAST COMPONENTS SUBJECTED TO HIGH CYCLE FATIGUE

摘要

In many studies on high cycle fatigue, failure occurs at the free surface or close to it. Consequently, therneffect of the environment and the surface treatment are of utmost importance. In the case of structures madernof spheroidal graphite cast iron, the presence of different kinds of initial flaws within the material explainsrnthe scattered fatigue lives. An expression for the cumulative failure probability depending of these initialrnflaws is derived. For tested suspension arms, this probabilistic approach is used to assess the fatigue lives byrntaking into account a flaw size distribution, a crack propagation law, the environment and the surfacerntreatment.