抄録
In order to investigate the fatigue strength behavior under fully reversed impact torsional load, two types of the impact fatigue tesing machines were newly developed. By using these testing machines, a series of experiments were carried out on a structural alloy steel JIS. SCM435.
The following characteristics of impact torsional fatigue strength behaviors were revealed : (1) the fatigue strength of the plain specimen in impact fatigue is higher than that in non-impact fatigue in the entire range of this experiment ;(2) the fatigue strength of the hole-notched specimen in impact fatigue shows a trend to become lower comparing with the results in non-impact fatigue in high stress cycles region ; (3) the crack growth rate in impact fatigue is lower than in non-impact fatigue.
