Cracking and slipping are ways to relieve stress. We are constructing a model using quantum and classical mechanics to describe the energy involved in cracking and sliding. The interphase, which may be only a few atoms thick, is the starting point of the behavior observed for the material as a whole, and capturing the behavior accurately requires atomistic and quantum simulations. The MSC is developing the tools to allow Rodin to do quantum simulations and apply them to practical problems of interest to the engineering community. A simulation by Vemaganti shows where damage begins, leading to a loss of local stiffness, in a composite with embedded particles.
Brighter colors correspond to higher effective stress in the inclusions after damage is initiated.
In one effort, the simulations will be enhanced by incorporating input from X-ray computed tomography. The Active Data Repository project at the University of Maryland, led by Joel Saltz, is developing just the sort of tools to handle these large tomography data sets. Farther down the road, the simulations will incorporate interaction tools for steering the computations, visualizing the results, and correlating computational and experimental data. At the moment, however, Rodin is focused on the Caltech collaboration. They will involve overcoming cultural barriers.