Mixed mode fatigue crack propagation in a ferritic–perlitic cold drawn tube

Autor: H. Desimone, Stefano Beretta, Angela Cerrini
Rok vydání: 2008
Předmět:
Zdroj: Engineering Fracture Mechanics. 75:845-856
ISSN: 0013-7944
Popis: Previous work by the authors has shown that torsional fatigue tests on cold drawn tube specimens with a longitudinal micronotch present both Mode III ahead of the crack tip (throughout the tube thickness) and Mode I at the defect edges. The co-planar Mode III propagation was prevalent and is followed by Mode II crack propagation along the cold drawn direction. In this work, this behaviour is further investigated by a new series of experimental tests together with a finite element analysis. The mechanisms behind this competition between Mode I and Mode III cracks are analysed and some fractographies were performed on run-outs, broken and interrupted tests. Indeed, pure Mode I and pure Mode II crack propagation rates along with mixed mode crack propagation rates are analysed. Finally, the conditions in order to get Mode I crack growth or shear driven propagation are discussed.
Databáze: OpenAIRE