Laboratoire Charles Coulomb UMR 5221 CNRS/UM2 (L2C)


Accueil > La Recherche > Axes & Equipes > Matière Molle & Verres > Equipe : Physique des Verres > Thème : Nanophysique des surfaces des verres

Measurement of 3D strain/stress field

par Sébastien LAYSSAC - publié le

Involved researchers : M. Ciccotti, M. George, A. Grimaldi, G. Pallarès

(Collaboration S. Roux – ENS Cachan)

In order to investigate in situ propagation of a crack by local scanning probe techniques, the knowledge of surface strain-stress field is vital especially around the corner point singularity that is the intersection between the crack front and the free surface. The mechanisms acting at a crack tip in glass are indeed strongly dependent on the stress gradient developing around the crack front. A novel integrated Digital Image Correlation technique applied on AFM images is being developed in collaboration with S. Roux (LMT-ENS Cachan) which gives access to stress intensity factor and out-of-plane displacement of the free surface at a crack tip. The results are confronted with measurements at larger scale by optical profilometry and finite element simulation to characterise the stress and strain fields.

Out-of-plane displacement field around the crack tip measured by DIC technique (a) raw residual field (b) fitted displacement field (c) remaining residual field after fit substraction (d) out of plane displacement - © L2C