異周期の曲げ・ねじり組合せ応力を受ける切欠き材のS-N線図に基づく疲労寿命推定法

抄録

In order to investigate the fatigue life of notched specimens under combined bending and torsion which were acting at different frequencies, a testing machine was deviced, and some experiments were carried out on three types of notched carbon steel specimens.
In the same way as that proposed in the previous paper, a modified Findley equation including the correction factor of different frequencies R^1/t was used as the criterion of fatigue life, (σ/σ_N)^1/ψ_N+(R^1/t·τ/τ_N)²=1
where σ_N, τ_N=fatigue strengths at N cycles
ψ_N=τ_N/σ_N
R=the frequency ratio of torsion to bending
t=the gradient of the S-N diagram of torsion
It was found that the method was applicable to the notched specimens also.