Rupture, damage and fatigue

External mechanical loads generate modifications of the ultimate behavior of the material. We are interested, for example, in the propagation of cracks in heterogeneous media, as well as in the influence of complex loadings (multiaxial) on the ultimate fate of the system.

Fatigue is treated through an energetic approach, since the 90’s, based on two energy parameters: (i) the first associated with an internal rate of energy, linked at the microstructural level to a reversible elastic behavior; (ii) the second entropic associated with a non-calorific dissipation . These
parameters represent only a fraction of the total mechanical energy. The associated mechanical model is able to reproduce accurately the thermomechanical effects generated by complex cyclic loads. The obtained results are thus relevant to multiaxial fatigue with complex loads.

Fracture propagation in multi-scale materials is studied both numerically and experimentally (in-situ visualization). The aim is to understand the role played by material heterogeneities (papers, concretes) on the nucleation, propagation and the dynamics of micro-cracks.

Phd students

• F. Villette (2017-2020) - Mécanique des papiers et hétérogénéités de structures
• C. Ningre (2015-2019) - Développement d’une méthode de suivi de l’endommagement par fatigue multiaxiale : Application aux turbines hydroélectriques - col. 3SR /  IRDL

Alumni

Engineers

• J. Noël (2016-2017) - PSPC Innov'Hydro : Analyse des sollicitations mécaniques subies par les turbines, production d'essais et de protocoles de fatigue pour la qualification des matériaux - col. 3SR / GE

Phds

• V. Krasnoshlyk (2013-2017) - Etude multi-échelles et multiphysiques des mécanismes de fissuration dans les matériaux à base de fibres naturelles . col. 3SR / LaMCoS / LGP2 / Univ. Uppsala (Suède)