A Model for Predicting the Stress Concentration of Intergranular Corrosion around a Fastener Hole

Abstract

This paper presents a model that predicts the stress field around intergranular corrosion. The stress analysis is conducted in ABAQUS via a Python input script, which is written in Igor Pro. The intergranular corrosion path is described using a Monte-Carlo Markov Chain based on the materials grain size distribution and probability that the corrosion will turn at a grain boundary junction. The model allows a complete analysis of the stresses resulting from intergranular corrosion around a fastener hole of any size. As fatigue initiation is most likely to occur at the highest stress concentration, this model gives an understanding of which of the features of intergranular corrosion are most critical and can allow for the development of beta solutions for crack growth. This model has been applied to 7075-T651 extruded aluminum alloy from a legacy era aircraft but can be readily applied to any material where the microstructure is known and can be described using a statistical distribution.