Modélisation élastoplastique de la densification des verres de silice sous des sollicitations de contact à l'échelle micrométrique.

Silicate glasses are known to be brittle at the macroscopic scale but they can also undergo plastic deformation at the microscopic scale. More specifically, plastic densification occurs under contact loadings. In this paper, a constitutive model, which allows to take into account this phenomenon, is presented. An identification of the material parameters using instrumented indentation results is proposed. This identification is based on the comparison of local residual indentation-induced densification field obtained using Raman spectroscopy and computational results. This constitutive model is then used to analyse the distribution of densification after three-dimensional Vickers indentation and Cube Corner indentation. Finally, a finite-element analysis of the scratch test is done to show the plastic densification of such materials under scratching conditions. These different results show that the size of the densified zone under indentation-scratch loading is strongly related to the contact size. [ABSTRACT FROM AUTHOR]