https://uwaterloo.ca/centre-advanced-materials-joining/sites/ca.centre-advanced-materials-joining/files/uploads/files/13_a_noroozi_2005.pdf

A two parameter driving force for fatigue crack growth analysis

The Merging of Fatigue and Fracture Mechanics Concepts: A Historical Perspective

Prediction of fatigue crack growth under real stress histories

The fatigue crack growth behaviour of 2024 T3 aluminium was investigated experimentally. The fatigue experiments were performed under constant stress amplitude, constant amplitude with single and multiple overloads and aircraft service spectra. The fatigue spectra used correspond to the air-to-air, air-to-ground and instrumentation and navigation flight phases. They were applied for different stress levels. In total 11 different random flight service spectra were examined. The retardation effects caused by the overloads on the fatigue crack growth behaviour and the fatigue crack growth under aircraft service spectra were predicted using an in-house-developed code. The code makes use of the strip plastic zone approximation to account for material hardening effects along the path of prospective crack growth. Crack growth is treated incrementally and corresponds to failure of material elements ahead of an existing crack after a certain critical number of fatigue cycles. For the simulation of irregular service spectra by equivalent sequences of distinguished stress cycles a modified rainflow counting method is utilized. Spectrum simulation accounts also for non-linearity in fatigue damage accumulation and load sequence effects. The computed fatigue curves fit well with the experimental results.

D Aliaga

Papers

A Simple Crack Closure Model for Predicting Fatigue Crack Growth Under Flight Simulation Loading