Jivkov's articles
Evolution of fatigue crack corrosion from surface irregularities
Abstract
A moving boundary model is presented for crack nucleation and growth from surface flaws. It concerns with chemical
attack that results in material dissolution. A controlling mechanism for evolution is the rupture of a brittle
corrosion-protective film that is built up along the corroding surface. The evolution rate is a function of the degree
of protective film damage caused by the surface straining. The problem is formulated for an elastic body containing
a single and double pits. Low-frequency cyclic loading is considered. Numerical solution is proposed. The behaviours
of a growing crack and of two competing cracks are described. Stages of incubation, blunting and steady-state growth
characterise a single crack evolution. The steady-state growth rate is found independent of the initial geometry.
Stages of independent growth, interactive growth and arrest of one crack characterise the evolution of two competing
cracks. The lengths of the arrested cracks are presented as functions of the ratio between the pit depth for a series
of different distances between the pits. It is emphasized that the solutions correspond to a homogeneous material.
Further work is required to account for the material microstructure.