Elasto-plastic analysis of critical fracture stress and fatigue fracture prediction

The purpose of this investigation is to obtain the critical fracture stress, σf, in a cracked elasto-plastic plate subjected to mixed-mode loading. A new model estimating the magnitude of critical fracture stress based on the plastic zone during crack propagation is developed. Subsequently, this concept is applied to predict crack growth due to fatigue loads. Apart from the obvious and ideal benefits of being able to quantify crack propagation rates without the necessity to determine empirical coefficients and exponents experimentally, such an approach would lead to a better understanding of the factors which affect the crack growth rate.