High Speed Plane Bending Fatigue Test : (2nd Report, On the Speed Dependency of the Endurance Limit)

Abstract

In order to investigate the effect of stress reversal speed (or frequency) on the endurance limit, the specimen of carbon steel and nickel-chrome steel were tested with the High Speed Pneumatic Fatigue Testing Machine developed by the author. The test results have shown that the endurance limit has a tendency to increase with frequency in the high frequency range, while it is independent of frequency in the low frequency range. The boundary frequency seemes to become higher according as the internal friction of the material decreases. These phenomena could be explaind rheologically with the visco-elastic model.