抄録
It was found reasonable to classify the forces imparted to any machine parts into dead load, live load and impact load. It appears that the actual fatigue failure, is connected with the impact load in question.
Considering that the material heterogeneity causes wave reflection in impact waves, the author proposes a metallographical method for increasing the resistance of the material against the impact force. It is also possible to reduce impact stress by changing the form of the machine parts.
A conception that the capacity for elastic energy absorption is very important for such a dynamic problem as fatigue, besides endurance limit, is here proposed.
