A new method of retarding fatigue crack growth on pressure vessels

An artificial wedge to retard;fatigue crack growth in tension has been inve stigated. The results show that an artificial wedge can reduce the growth r ate of fatigue crack on surface fatigue crack and, the fatigue crack growth behavior is essentially similar in-depth and width directions. Based on a theoretical analysis, a model for the effective crack growth parameter Delt aK(eff) is presented. It is shown that the relationship between the calcula ted DeltaK(eff) value and crack speed are almost the same as those of crack ed specimens without a wedge. Therefore this model can be applied to estima te retardation behavior.