Soutenance de thèse : Amin AZMAN

In-situ characterisation of ductile damage using X-ray tomography analysed by automatic cavity tracking

Doctorant : Amin AZMAN

Laboratoire INSA : Mateis

Ecole doctorale :  ED34 : Matériaux de Lyon

Damage evolution in ductile metals is characterized by the nucleation, growth and coalescence of small internal voids. Many laws and studies have been developed to understand and predict damage. In the past decade, X-ray tomography has been shown to be an adapted tool for characterizing damage. Due to its 3D imaging and most importantly non-destructive capabilities, it brings the possibility to not only obtain more accurate qualitative data, but also for quantitative analysis of damage.

In this study, in-situ characterisation using synchrotron X-ray tomography were performed on a huge number of pure metals of different crystal structure (HCP, FCC, BCC) to see the effect of crystal structure on ductile damage. Studies on damage evolution are usually based on a statistical mean-field approach. An automatic tracking algorithm was further developed as a complementary way of analysis, which follows the voids individually. This allows us to separate the 3 damage mechanisms and study the nucleation, growth and coalescence of voids in more detail. The data obtained were analysed using both the classical statistical approach and with the tracking algorithm.

Experiments were also performed on different geometry samples to see the influence of triaxiality on ductile damage.