Crack Tip Plastic Zone Effect on Fatigue Crack Propagation
摘要
It has been shown in the previous section that the fatigue crack propagation in metallic materials follows a trend that can be described by the Paris-Erdogan Eq. ( 10.10 ). However, the Paris postulate is valid only under particular circumstances as constant load cycling in Region II of fatigue, long cracks and stress ratio R equal zero. If these circumstances are not met the Paris-Erdogan equation fails to represent the FCGR of the material.