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从理论上导出了塑性材料或低缺口敏感材料的有效应力集中系数K_f与理论应力集中系数K_t和硬化指数n之间的定量关系:K_f=K~(2/(2+n))计算了缺口疲劳极限△σ_RN和K_f,计算值和测量结果相符,误差一般小于10%。讨论了K_f和△σ_RN的物理意义,提出了疲劳强度应力集中系数K_a=K_t~2+2n/3+n和疲劳强度应变集中系数K_t=K~4/3+n,并得到了从△σ_RN向△K_th应力转变的应力集中系数K_t~*=(△σ_R/△σ_th)~3+n/2最后还导出了Frost规律σ_th~3·a=c中c与σ_R和裂尖半径ρ~*的关系。
The quantitative relationship between the effective stress concentration factor K_f and the theoretical stress concentration factor K_t and the hardening index n of plastic material or low-notch material is deduced theoretically: K_f = K ~ (2 + n) Fatigue limit △ σ_RN and K_f, calculated values and measurement results, the error is generally less than 10%. The physical meaning of K_f and △ σ_RN are discussed. The fatigue stress concentration factor K_a = K_t ~ 2 + 2n / 3 + n and the fatigue strength strain concentration factor K_t = K ~ 4/3 + n are proposed. The stress concentration factor K_t ~ * = (Δσ_R / Δσ_th) ~ 3 + n / 2 which is transformed to △ K_th stress is also deduced. Finally, the relationship between c and σ_R in Frost rule σ_th ~ 3 · a = Relationship.