Amit Acharya
Department of Civil & Environmental Engineering, Carnegie-Mellon University

Wednesday, October 26, 2016 3:35pm - 4:25pm
103 Leonhard Building

Abstract:
Terminating lines of surfaces of discontinuity serve as a model of common line defects that arise in a host of materials; dislocations and grain/phase boundary junctions in crystalline and soft matter. I will describe a framework for considering line defect dynamics within continuum mechanics. The theory will be illustrated with examples related to dislocation dynamics with inertia, dislocation nucleation, and the computation of fields of interfacial defects like the star disclination and grain boundary disconnections.

Bio:
Amit Acharya is a Professor in the Mechanics, Materials, and Computing group of the Department of Civil & Environmental Engineering at Carnegie Mellon University (CMU). He also holds a courtesy appointment in the Dept. of Materials Science and Engineering at CMU and a Visiting Professorship in the Dept. of Mathematical Sciences at the University of Bath, UK. He received a PhD degree in Theoretical & Applied Mechanics from the University of Illinois at Urbana-Champaign (UIUC) in 1994. Subsequently, he did post-doctoral work for a year at the University of Pennsylvania and then worked for HKS, Inc. in Providence, RI (now Simulia, Dassualt Systemes) from 1995-1998, spending most of his time as a senior research engineer in the ABAQUS Std Development group. There, he was the lead developer of the *Hysteresis nonlinear viscoelastic material model and the S4, fully-integrated finite strain shell element, that are still in use in the ABAQUS general-purpose FE code. From 1998-2000, he was a Research scientist at the DOE-ASCI funded Center for Simulation of Advanced Rockets at UIUC, before joining CMU in 2000.
His honors include a Leverhulme Visiting Professorship from the Leverhulme Foundation, UK, a Rosi and Max Varon Visiting Professorship from the Weizmann Institute, Israel, and an INdAM Visiting Professorship to the University of Pavia, Italy. He has been an invited short-course lecturer at SISSA (Trieste, Italy) and has held visiting research positions at Oxford, Cambridge, Marseille, Edinburgh, and Metz.
His broad research interests are in Continuum Mechanics, Mathematical Materials Science, and Applied Mathematics. Current emphasis is on theoretical and computational defect mechanics in crystalline, liquid crystalline, and metallic glass systems, coarse-graining of nonlinear time-dependent systems and the interplay of differential geometry and structural mechanics in the design and actuation of thin sheets.