The effect of crack wake characteristics on fatigue crack closure: Part II — a non-uniform wake study

Abstract

In this second paper of the two-paper series the effect of overloads, causing local anomalies in the crack wake, on the closure load and load-CMOD behavior is studied using the RICC model. The closure load level is found to decrease immediately after the application of the overload because of the gross plastic deformation at the crack tip and the crack tip blunting effects. It is shown that with further crack growth beyond the overload plastic zone, the crack surface contact may start at the overload site resulting in relatively high contact load levels. The variation in the contact load level with crack length is formulated using the RICC model. The proposed behaviors are experimentally verified for a Ti-6Al-4V alloy.