Estimations of the T-Stress for Small Cracks at Notches

The T-stress is increasingly being recognized as an important additional stress field characterizing parameter in the analysis of cracked bodies. Using T-stress as the constraint parameter, the framework of failure assessments including the constraint effect has been established; and the effect of T-stress on fatigue crack propagation rate has been investigated by several researchers. In this paper, a simple method for determining the T-stress for small notch-emanating cracks is presented. First, the background on the T-stress calculation using the superposition principle and the similarities between the elastic notch tip stress fields described by two parameters: the stress concentration factor and the notch-tip radius, are summarized. Then, the method of estimating T-stress for both short and long cracks at the notches is presented. The method is used to predict T-stress solutions for edge notched plates under remote tension with cracks emanating from the notches. A wide range of notch and crack geometries are considered and the results are compared to the available T-stresses solutions in the literature. Good agreements have been achieved. The method presented here can be used for a variety of notch crack geometries.