疲労き裂発生に及ぼす繰返し速度の影響

概要

論文の詳細を見る
The effect of stress frequency on fatigue crack initiation in 99.5 percent pure titanium, which has remarkable strain rate dependence in plastic region was studied. Fatigue crack initiation tests were carried out under three frequencies (20 Hz, 1 Hz, 0.2 Hz). An elasto/visco-plastic analysis was performed by the finite element method (FEM), and the comparison between the cycles to crack initiation and the viscoplastic strain range at notch root obtained by analysis was made. The results obtained in this study are summarized as follows: (1) It was found from the experiments that the cycles to crack initiation depended on stress frequency, and were approximately in proportion to f^n(n<0),where f is the stress frequency. (2) The effect of stress frequency on the fatigue crack initiation may be explained by the variation of viscoplastic strain range at notch root resulting from the strain rate dependence of the material. (3) A parameter related closely to the fatigue crack intiation is the visco-plastic strain range at the notch root part of stress concentration.
社団法人日本材料学会の論文
1985-02-15