超長寿命フレッティング疲労き裂の発生と伝ぱ

概要

論文の詳細を見る
In fretting fatigue, a fatigue crack initiated from the contact edge can be found even in the specimen which survives up to 10^7 cycles. This fact means that fretting fatigue fracture may occur if the specimen undergoes very long fatigue cycles (more than 10^7 cycles). To characterize the fatigue properties of very long life fretting fatigue, it is necessary to understand the effect of the singular stress field near the contact edge on the crack initiation and propagation. In this study, fretting fatigue tests below the fatigue limit (corresponding to 10^7 cycles) were carried out. The fatigue tests were interrupted at 10^7 cycles, and the fatigue cracks were observed by SEM. Numerical analysis by FEM was also carried out. It was found that the fatigue crack initiation at the contact edge could be evaluated by the stress intensity coefficient of the singular field, and the crack propagation/non-propagation could be estimated by △K_<θmax> in the direction of △σ_<θmax>, with an introduction of an initial crack with the critical length over which the linear fracture mechanics can be applied.
社団法人日本材料学会の論文
2002-07-15