MMAE Seminar - Dr. Ankit Srivastava - Phononics and Metamaterials

Armour College of Engineering's Mechanical, Materials & Aerospace Engineering Department will welcome Dr. Ankit Srivastava, Assistant Professor in the Mechanical, Materials, and Aerospace Engineering Department of IIT on Wednesday, September 27th, to present his lecture, Phononics and Metamaterials.

Abstract

In this talk, I will consider the areas of Phononics and Metamaterials from a computational and theoretical perspective. Since Metamaterials builds upon the area of Phononics, I will first consider the computational requirements in the latter field. The solution to these requirements will be considered within the confines of a mixed-variational scheme. I will present some representative results which will establish the speed, convergence, accuracy, and simplicity of expression of the algorithm. This algorithm is implemented on distributed Graphical Processing Units for further computational acceleration. I will present results on the application of this computational platform towards the solution of a topology optimization problem for 3-D phononic crystals. I will close the discussion of Phononics with the description of the problem of level repulsion and its solution which is essential for the correct and efficient sorting of the phononic band-structure.

In the second part of the presentation, I will consider the problem of metamaterials, specifically concentrating on some broad problems in the field. I will consider the field of metamaterials from the perspective of causality and elucidate certain universal constraints on metamaterial constitutive tensors which follow. Finally, I will elucidate the central problem with metamaterial applications: the issue of ignored evanescent waves at their boundaries, and will propose a tentative solution to mitigate the issue. This issue will be considered within the confines of a simple 1-D problem. In the process, I will show how a simple 1-D laminate can exhibit exotic metamaterial wave phenomenon such as negative refraction.

Biography

Dr. Ankit Srivastava is an Assistant Professor in the Mechanical, Materials, and Aerospace Engineering department at the Illinois Institute of Technology in Chicago. He received his undergraduate degree in Civil Engineering from the Indian Institute of Technology Guwahati. He has an M.S. and a PhD in Structural Engineering from the University of California San Diego (UCSD, advisor: Dr. Lanza di Scalea). He was also a postdoctoral researcher with Dr. Sia Nemat-Nasser. His general research interests include wave propagation, homogenization, computational solid mechanics, large scale CPU-GPU computing, and topology optimization.