ESPCI web site
Disorder and Acoustic Properties : the vibrations as predictors for plastic damage in glasses
The mechanical response of glasses is full of unexplained properties, like the composition dependence of its plastic response. In this talk, we will first review the elasto-plastic response of amorphous materials, and then focus on their vibrational properties.
The propagation of vibrations in disordered materials is also responsible for their high heat capacity and low thermal conductivity. We will see that is can be related to multidimensional couplings. The resulting "non-affine" displacement field and elastic heterogeneities give rise to a scale dependent mechanical response. The evolution of the elastic heterogeneities upon mechanical deformation affects directly the shape and distribution of vibrational eigenmodes. We will see how this effect can be used to predict damage in various disordered materials, like silicate glasses and amorphous silicon.