MMAE Seminar - Predicting New Mechanisms Exploiting Heterogeneity

Armour College of Engineering's Mechanical, Materials & Aerospace Engineering Department will welcome Dr. M. Zubaer Hossain, Postdoctoral Scholar at California Institute of Technology, to campus on Monday, March 23rd to present his lecture, Predicting New Mechanisms Exploiting Heterogeneity.

Abstract

Discovering new materials and technologies is essential for finding solutions to our problems in energy, security, health, and nanotechnology. While homogeneous materials have provided numerous breakthroughs over the years in these sectors, heterogeneous materials (which offer significantly more functionalities to explore, design, and control) have been relatively less exploited. Consequently, there is an intense interest in creating new materials and properties using heterogeneity as an engineering tool for a range of application areas, including composites, nanotechnology, energy, and defense.

However, theoretical difficulties and experimental challenges make it a demanding task to study heterogeneous materials, regardless of their application areas. This is due to intricate deformation fields at multiple length scales and their complex coupling with multiphysical phenomena, which are ruled by classical and quantum mechanics principles. Predictive theories are, therefore, constrained by approximations, and our ability to design materials remains bounded within disciplinary boundaries. This talk concerns addressing that limitation by developing multiscale methods and predicting the implications of heterogeneity often buried under homogenization approximations. I will discuss two examples to demonstrate the importance of considering the exact details of heterogeneity. In the first example, I will discuss the implication of heterogeneity in the context of fracture at the continuum scales and show pathways for creating fundamentally new toughening mechanisms based on elastic-geometric heterogeneity. In the second example, I will demonstrate nanoscale heterogeneity as a mechanically controllable design variable to improve the energy absorption ability of solar cells. These efforts enabled the revealing of new, inaccessible mechanisms under existing computational techniques or simplifying approximations.

Biography

M. Zubair Hossain is currently a Postdoctoral Scholar at the California Institute of Technology. He also holds a Visiting Scholar appointment at Johns Hopkins University and worked as a Visiting Scientist at the Lawrence Livermore National Laboratory. He obtained his Ph.D. degree in mechanical engineering in 2011 from the University of Illinois at Urbana-Champaign (UIUC), and his research interests involve understanding the mechanics of heterogeneous materials with applications in energy, defense, nanotechnology or aerospace.