Fatigue life assessment for material containing defects under multiaxial loading

¹ Laboratoire de Génie Mécanique, Université de Monastir, Institut préparatoire aux études d’Ingénieurs de Monastir, Avenue Ibn El Jazzar, 5019 Monastir, Tunisia
e-mail: anouar.nasr@hotmail.fr
² Institut Pprime, CNRS, UPR 3346, ISAE-ENSMA, Université de Poitiers, Département Physique et Mécanique des Matériaux, Téléport 2, 1 Avenue Clément Ader, BP 40109, 86961 Futuroscope Chasseneuil Cedex, France
³ Laboratoire de Mécanique de Sousse, Ecole Nationale d’Ingénieurs de Sousse, BP 264, Sousse Erriadh 4023, Tunisia

Received: 28 January 2016
Accepted: 26 September 2016

Abstract

In the first part, a methodology will be proposed for calculating the multiaxial fatigue limit in the presence of defects by using the defect stress gradient (DSG) approach. The proposed approach will be validated for two materials: 1045 steel containing artificial surface defects and ferritic nodular cast iron (NCI) containing natural shrinkages. In the second part of this paper, an extension of the DSG criterion to finite life is proposed. Experimental investigations aim to identify the application limits of an initiation fatigue criterion for finite fatigue life domain in the case of defective material.