抄録
With the increase in the speed of railway trains higher equipment is demanded for the safety of the axles of the rolling stock against fatigue strength. The crack initiation of fracture on the axles usually occur in press fit parts, and the ratio of the crack initiation in these parts have formed over 90% of the total. It is necessary then to investigate the fatigue strength on the press fit part, i.e. the wheel-seat, the dust guard seat etc. in order to study fatigue life of the axles. But in estimating the fatigue life of the axles the usual fatigue tests on specimens are inadequate for data since the press fit parts are subject to the effect of stress concentration and fretting, and there are not sufficient data concerning fatigue strength on the press fit parts.
In this monograph, the current researches in practice at the present time on the strength of the axles are reported, and the problems concerning the estimation of fatigue life of the axles, the initiation and propagation of crack and the application of cumulative damage law are discussed. To solve the problems concerning the fatigue strength of the axles, researches are required on the following items.
(1) The estimation of fatigue damage due to service load.
(2) The effect of the load variation in the initiation and propagation of crack in the press fit parts.
(3) The fatigue strength under superposed mini sinusodial stress wave and shock stress wave.
(4) The fatigue strength under the fretting phenomena.
(5) The fatigue tests repeated 108∼109 times.
