抄録
In this paper, the fatigue crack initiation and growth behavior of steel test specimens was observed by in-situ observation. In order to do that a specially designed small fatigue testing machine has been developed using piezo-electric actuators. Under a laser microscope, the surface roughness changes in steel test specimens with stress cycle at different levels of applied load have been measured, and the quantitative relations between roughness change, stress amplitude and number of cycles have been obtained.
