The analysis of an initial crack growth from a notch

Abstract

The first stage of fatigue is a important problem because its width is very short but its life is 80% of the whole life. But it is well known that the initial crack growth is very fast on the condition of existing compressive stress. The reason is that an crack opening is arose on the behalf of a remained tensile stress. Therefore, in this study the effect of an compressive stress was investigated. As results, it was found that the acceleration of initial crack growth is in the proportion to the power of the compressive stress and striation was found in the initial crack.