Description:

Stochastic Mechanics: Further Empowerment for Materials-by-Design

Rapid development of new structural materials through a materials-by-design framework requires closure of the communications gaps that have traditionally existed between modelers, experimentalists, and materials processors. For example, the modeler can identify constitutive parameters that have a significant effect on the predicted response of a material; however, the materials processor can rarely control these constitutive parameters directly. Therefore, more physically based models that include explicit representation of the primary actors, such as microstructural features, promise results that inform the materials processor about quantities they can try to control. Closure of this entire materials-by-design loop also provides a much clearer problem statement regarding the many uncertainties that exist at every step of the process: the random microstructure drives localization of failure; inexact measurements in characterization and testing lead to potential errors in our understanding of the true state of the material; and, environmental uncertainties affect the formation of the material during processing. These challenges call for the stochastic mechanics community to bring their significant expertise to bear on this problem. Probabilistic evaluation of materials characterization data, novel stochastic simulation of material microstructure, and efficient surrogate models to represent structural/material response in multi-scale models are only a few of the tools that can further enable materials-by-design approaches. This talk will discuss these tools in the particular context of brittle materials under high-rate compression, with a brief discussion of other applications in composite materials and polycrystalline metals.

Lori Graham-Brady is Professor and Chair of the Civil Engineering Department at Johns Hopkins University, with secondary appointments in Mechanical Engineering and Materials Science & Engineering. Her research interests are in computational stochastic mechanics, multiscale modeling of materials with random microstructure and the mechanics of failure under high-rate loading. She is the Associate Director of the Hopkins Extreme Materials Institute and Director of an NSF-funded IGERT training program with the theme of Modeling Complex Systems. She has received a number of awards, including the Presidential Early Career Awards for Scientists and Engineers (PECASE), the Walter L. Huber Civil Engineering Research Prize, and the William H. Huggins Award for Excellence in Teaching.