Non-propagating cracks in notched components at the fatigue limit analysed with a microstructural model. (June 2018)

• Record Type: Journal Article
• Authors: Chaves, V.; Madrigal, C.; Navarro, A.
• Is Part Of: Theoretical and applied fracture mechanics. Volume 95(2018)
• Page Start: 119
• Page End: 126
• Publication Date: 2018-06
• Subjects: Non-propagating crack -- Fatigue limit -- Notch -- Fracture Mechanics -- Stress gradient; Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2018.02.008
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: Study of non-propagating cracks (NPCs) at notches. NPC length at the fatigue limit predicted with the NR model. The input is the linear elastic stress gradient ahead of the notch. The K t effect and the notch-size effect are studied. Predictions are close to the experimental results from the literature. Abstract: The presence of non-propagating cracks at notches subjected to cyclic loads around the fatigue limit is well known. The basic reason for their formation is the existence of a stress gradient created by the notch, which can initiate a crack but not its propagation through the solid. In this paper, the application of the Navarro and de los Rios microstructural model (NR model) for the length prediction of non-propagating cracks is presented. A simplified version of the NR model has been used, that basically requires the elastic gradient in front of the notch, which can be easily achieved using finite element analysis. The model correctly predicts the difference in length of non-propagating cracks between sharp and blunt notches and between small, medium and large notches. Finally, the non-propagating crack lengths taken from the literature have been analysed, and the predictions provided by the model are relatively close.