Stefanos Papanikolaou (West Virginia Univ., USA): Noise in nanoscale crystal plasticity: What can we learn from it?

Rare, abrupt events are common in plastically deforming crystals at small scales. Despite the spatial self-averaging of large samples, these abrupt events may control the behavior of sub-micron representative volumes in multiscale modeling or in delicate mechanical probes such as nanoindentation. The very origin of abrupt events is the presence of quenched disorder: either in the form of inclusions or parent dislocation configurations. In this talk, I will discuss various properties of these strain bursts in minimal modelling of nanopillar compression (rate effects and ensemble average behaviors) and then, I will discuss the form of the parent quenched disorder distributions that typically originate in prior mechanical processing, and their role in the compressive yield mechanical properties. Finally, I will discuss possible ways of inferring the quenched disorder distributions directly from the analysis of the noisy response.