The effect of local loads on fatigue crack growth

摘要

Crack growth is usually dominated by the remote boundary loads on the cracked body. However when cracks are small, local loads can have a substantial effect on the crack growth behaviour. These local loads often arise due to fretting, that is the rubbing together of surfaces. If frictional forces are present, then non-linear effects must be taken into account. In general fatigue crack growth is determined by triangle openK (the range of the stress intensity factor) and R (the ratio of minimum K to maximum K). This paper demonstrates, for a simple model, the effects on both triangle openK and R caused by localized freeting forces.