Microplasticity and energy dissipation in very high cycle fatigue

Véronique Favier (1) , Ngoc-Lam Phung (1) , Nicolas Ranc (1) , Thierry Bretheau (1) , Jacques Groslafaige (1) , Gérard Roger (1) , Wilfrid Seiler (1) , Frédéric Valès (1) , Danièle Wagner (2) , Chow Wang (2) , Claude Bathias (2) , Julie Cédelle (2) , Isabelle Ranc (2) , André Chrysochoos (3) , Antoine Blanche (3) , Bertrand Wattrisse (3) , Gille Camp (4) , Alain Clary (4) , Yves El Kaïm (5) , Franck Jourdan (6) , Fabienne Grégori (7) , Brigitte Bacroix (7) , André Galtier (8) , Guillaume Thoquenne (8) , Haël Mughrabi (9)

1 PIMM - Laboratoire Procédés et Ingénierie en Mécanique et Matériaux
2 LEME - Laboratoire Energétique Mécanique Electromagnétisme
3 ThM2 - ThermoMécanique des Matériaux
4 LMGC - Laboratoire de Mécanique et Génie Civil
5 Servex - Moyens expérimentaux
6 CGB - Couplages en Géomécanique et Biomécanique
7 LSPM - Laboratoire des Sciences des Procédés et des Matériaux
8 CETIM - Centre Technique des Industries Mécaniques
9 FAU - Friedrich-Alexander Universität Erlangen-Nürnberg = University of Erlangen-Nuremberg

This paper present the ongoing DISFAT project financially supported by the French National Agency ANR and its white program. It aims at a deeper understanding of mechanisms leading to crack initiation in metals and alloys in Very High Cycle Fatigue (VHCF). In contrast to conventional fatigue tests, detecting irreversible microstructural changes using cyclic stress-strain curves analysis is no more possible, at least with conventional measurement systems, since the macroscopic behavior is quasi-elastic. To cope with this problem, we propose to use the energy signature of the deformation mechanisms. The main challenge of this project results from the fact that the energy and mechanical manifestations as well as the microstructural "evidences"of the mechanisms of interest involve very low signal. In this paper, we explain our strategy and present some results on fcc and bcc single-phase polycrystals.

Domaines: Matériaux; Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]; Mécanique des solides [physics.class-ph]; Mécanique des solides [physics.class-ph]; Thermique [physics.class-ph]; Thermique [physics.class-ph]

Véronique Favier, Ngoc-Lam Phung, Nicolas Ranc, Thierry Bretheau, Jacques Groslafaige, et al.. Microplasticity and energy dissipation in very high cycle fatigue. Fatigue Design 2011, 2011, Senlis, France. ⟨hal-00858854⟩