Séminaire exceptionnel du LPTMS: Srikanth H. Sastry

Amorphous solids are microscopically disordered materials that arise in diverse contexts, with polymeric glasses and soft glassy materials like gels and metallic glasses being some typical examples. The mechanical response of amorphous solids is distinct in microscopic detail from that of crystalline solids, and is of practical interest because of the relevance of the elastic and plastic response and rheology of these substances to a variety of processes and applications. A computational investigation of the response of a model amorphous solid to oscillatory deformation is presented, after a brief overview of current approaches to understanding mechanical response of amorphous solids. A dynamical transition is observed as the amplitude of the deformation is varied: For large values of the amplitude the system exhibits diffusive behavior and loss of memory of the initial conditions, whereas localization is observed for small amplitudes. The formation of memory in such systems of single and multiple inputs is also described.