A modified critical distance method for estimating fretting fatigue life of dovetail joints

In this paper, a modified theory of critical distance (TCD) method (i.e., Gradient-TCD method) is proposed, which combines fatigue parameter gradient and the TCD, to estimate fretting fatigue life of dovetail joints. The advantage of Gradient-TCD method lies in utilizing the gradient parameters to effectively characterize the local effect zone caused by fretting, thereby enabling the determination of a suitable critical distance length independent of material fatigue parameters. The reliability and predictive capability of the method is validated through experimental results. Furthermore, this method demonstrates insensitivity to mesh size, resulting in an 83.6% reduction in computational time while maintaining the predictions within the two-times scatter band. The novel Gradient-TCD method may provide an efficient and reliable approach for fretting fatigue life prediction, which holds promise for evaluating complex full-scale fretting problems. A Gradient-TCD method was proposed to determine the length of critical distance. The Gradient-TCD method effectively predicts the dovetail joints fretting fatigue life. Its insensitivity to mesh size results in an 83.6% reduction in computation time. It provides a promising solution for full-scale fretting fatigue evaluation.