動クリープおよび高温疲労の寿命に関する一考察

抄録

For prediction of the rupture life of metals subjected to reversed stressing of stress amplitude σ_a under a constant mean stress σ_m at elevated temperatures, the linear damage rule was adapted and its rupture life was analized by partitioning of parameter A, or the stress ratio σ_a/σ_m. In the range of 0≤A≤1, an equivalent static stress σ_me for rupture life was determined by use of A and slope α_t of rupture life curves based on σ_m. If rupture life curves of static creep are given, it is possible to predict approximately the rupture life curve of dynamic creep by calculation. In the range of 1≤A≤∞, an equivalent alternating stress σ_ae for fatigue life was determined by using A and slope α_t of completely reversed life curves based on σ_a. Therefore, a fatigue life curve for any mean stress will be predicted analytically from the completely reversed fatigue life curves.