平滑および切欠試験片の疲労強度の整理法と定式化の基礎概念

（切欠効果の材料依存性と寸法依存性を考慮するための方法と原理ならびに応用について）

抄録

A study for diagraming and formulating fatigue strength of notched and un-notched specimens has been developed. As a result, two fundamental and important concepts have been proposed; a hypothesis of cyclic plastic adaptation and a size effect criterion based on a normalized yield zone growth curve. From the former concept, an equivalent cyclic stress ratio is derived as a primary parameter correlating a cyclic stress condition of the notched specimen with that of the un-notched specimen, and a fatigue strength diagram is formulated for a large-sized notch and un-notch type specimen. From the latter, a secondary parameter quantifying concretely the size effect is derived and inserted in the equation of the fatigue strength diagram. In the present paper, a principle and methodology, and a perspective of the approach are discussed with reviewing the outline of the study.