About the Interfacial Multiphysics Lab
A basic premise in structures and materials research is to join two disparate materials/structures to form new and better materials/structures which have interfaces. Most of the time it works. However, when it does not work, those results are catastrophic. Our lab analyzes the effect of interfaces on material failure properties. Scientifically, the collective focus is on myriad aspects of multihpysical behavior of interfaces in materials that includes electronic, phononic, and lattice translational attributes which ultimately affect defect formation, defect propagation, and microstructure dependent material failure. (Therefore, the name Interfacial Multiphysics..)
Emphasis of our lab's work is on the multiscale simulations and experimentation. Our particular focus is on predicting and analyzing material failure in extreme environments. Extreme environment material behavior (such as ultra-high temperatures, nuclear radiation damage scenarios, high temperature coupled fluid structure interactions (turbines), hypersonic flights, high temperature high strain rate loadings, or stress corrosion cracking) is a complex topic. In such environments, mechanical as well as functional (phonon thermal conduction, electron mobility etc.) properties play important role in strength, strain rate, resistance to temperature and corrosion, which govern the reliability and performance. This co-dependence becomes even more important when complex materials with multiple interfaces are involved. The lab has shown the coupling between thermal (electronic as well as phononic thermal conduction) and mechanical properties in a variety of materials using experiments as well as models (a range of modeling and experimental publications). The lab also has recently shown that electron density of states, bond strength, phonon dispersion relations, and grain boundary internal structure strength are strongly correlated to each other and a well formed analytical relation can describe such relation (Published in Int. J. Plasticity). Using the modeling and experiment based advances, the lab has established the need to incorporate functional and mechanical property co-dependence in material failure models for extreme environment materials.
Advances in the Interfacial Multiphysics Lab are based on a unique combination of experimental platforms combined with a software centric approach where a new suite of quantum mechanical, classical molecular, coarse graining/multiscaling, and microstructure dependent failure models developed in the lab are used. A new experimental paradigm based on performing nanomechanical and micromechanical measurements at ultra-high temperatures in combination with Raman spectroscopy (Published in Journal of Engineering Materials and Technology and Materials Science and Engineering-A, 2010-11, AIP Review of Scientific Instruments, 2014) has been developed. The model developments include: (a) a new non-equilibrium Green’s function (NEGF) based formalism to understand interfacial thermal and mechanical properties under the influence of high temperature and extreme environment assisted phase transformation in nanostructured materials (published in J. Europ. Ceram. Soc. 2012 and J applied Physics 2013), (b) a new variant of the cohesive finite element method (CFEM) to analyze microscale failure in composites with an account of stochasticity in material properties (Engineering Fracture Mechanics, 2005); and (c) two different variants of molecular simulation methods (1). hybrid Monte Carlo method-2006 published in Physical Status Solidi-a and Journal of Applied Physics, and (2). equivalent crystal method-2009-10 published in Sanford publishing book, Physical Status Solidi-a and Journal of Nanomechanics and Micromechanics) for speeding up non-equilibrium molecular simulation timescales.
Below, two related publications are mentioned. One outlines a petascale and exascale computing based approach to materials design and Integrated Computational Materials Engineering (ICME) where lab has been playing important roles. The other, more recent one, outlines importance of scientific advances made in the lab.