Multi-parameter MTS criterion used for estimation of the crack deflection angle near a corrosion pit

Abstract

: Combined fatigue and corrosion damage is very typical for metal materials subjected to aggressive environment. Unfortunately, this topic is still not described sufficiently. Thus, a high strength steel specimen was subjected to a numerical analysis studying the mutual interaction of a fatigue crack and a corrosion pit within this work. Finite element method was utilized to model an inclined surface crack near a corrosion pit and then, the multi-parameter form of maximum tangential stress criterion was applied to estimate the crack deflection angle. Because the simulations were linear and parametric, it was easy to investigate effect of individual parameters on the results obtained. In the paper presented, the influence of the crack length, the number of the Williams expansion terms considered for tangential stress approximation and the critical distance, where the fracture criterion was applied, is discussed. The conclusions formulated based on the results of the study shall help to better understand how the fatigue crack behavior can be affected via presence of corrosion defects.