Consequently, tracking microstructural changes in materials under extreme conditions in 4D (time
and space) using in-situ analysis in atomistic simulations represents a significant but essential milestone.
It provides unmatched insight into dynamic processes at the atomic scale, enabling the observation
of real-time transformations and mechanisms that govern material behavior under high temperature
and pressure. The temporal resolution gained from tracking helps identify the rates and pathways of
microstructural evolution, crucial for understanding material stability and performance.Specifically, the spatial resolution of atomistic simulations enables the detailed examination of crystal
defects such as dislocations, twinning, vacancies, and pores. These defects play critical roles in
initiating dynamic phase transformations, melting/solidification processes where grain/phase boundaries
are present, or damage. By mapping these changes in four-dimensional space, we gain insight into
the statistics of their temporal occurrences and spatial correlations. This approach allows us to establish
connections between their evolution and key collective effects in out-of-equilibrium material behavior.
Consequently, this will lead to more accurate predictive models that account for the complexity at the
microscopic scale.
In summary, integrating 4D tracking within atomistic simulations represents a potent approach to
materials science, providing deeper insights into microstructural dynamics. This work leverages recent
advancements in the exaNBody HPC platform and an in-situ clustering method recently implemented
in the ExaStamp molecular dynamics code at CEA. This method utilizes a parallelism framework
to project discrete information onto a 3D Eulerian grid, facilitating on-the-fly clustering. The objective
of this project is to extend these capabilities to a 4D context to monitor the temporal evolution of
clusters. This extension will enable dynamic graph analysis, allowing not only the tracking of aggregate
distributions in volume and shape but also their temporal properties and time clustering behaviors.Conformément aux engagements pris par le CEA en faveur de l'intégration des personnes en situation de handicap, cet emploi est ouvert à tous et toutes. Participant à la protection nationale, une enquête administrative est réalisée pour tous les salariés du CEA afin d'assurer l'intégrité et la sécurité de la nation.