Phononic Crystals and Metamaterials For Enhanced Energy Harvesting...
Merhabalar,
21 Mart günü, 13:50-14:40 saatleri arasında Kompozit Teknolojileri Mükemmeliyet Merkezinde, Alper Erturk, Ph.D Associate Professor & Woodruff Faculty Fellow,G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology " Phononic crystals and metamaterials for enhanced energy harvesting and vibration attenuation" başlıklı seminer verecektir.
Sabancı Üniversitesi -Teknopark Gidiş
Teknopark- Sabancı Üniversitesi Dönüş
Araç Hareket Alanı : KTMM Binası Önü
Title: Phononic Crystals and Metamaterials For Enhanced Energy Harvesting and Vibration Attenuation
Speaker: Alper Erturk, Ph.D Associate Professor
Time: March 21, 2018, 13:50-14:40
Place: Teknopark- KTMM
Abstract:
Following a brief overview of our research activities in the Smart Structures & Dynamical Systems Laboratory at Georgia Tech, this talk will review our recent efforts on the leveraging of phononic crystals and metamaterials in structure-borne wave energy harvesting and vibration attenuation. In the first part, the two approaches of interest for elastic wave focusing and energy harvesting are the use of lens and mirror structures. In the first lens scenario, we will discuss our computational and experimental results on the focusing and harvesting of plane waves by means of a Gradient-Index (GRIN) Phononic Crystal (PC) lens. The proposed GRIN-PC lens is formed by an array of blind holes with different diameters. The blind hole distribution is tailored to obtain a hyperbolic secant profile of refractive index for the lowest antisymmetric Lamb wave mode. The second lens concept is an omnidirectional PC Luneburg lens with hexagonal unit cells hosting blind holes, and it alleviates the directivity issue due to its axisymmetric refractive index profile. In both of these GRIN-PC lens concepts, a piezoelectric energy harvester located at the focus yields an order of magnitude larger electrical power as compared to the baseline case of harvesting on the flat plate. We will also review our structurally-embedded elliptical and parabolic mirror concepts for reflective focusing and energy harvesting in a flat aluminum plate hosting blind holes with metallic (e.g. tungsten) inclusions. The second part of this talk will summarize our recent work on locally resonant (LR) mechanical and electromechanical metamaterials and metastructures. Specifically, we will summarize our general theoretical framework and its experimental validation for low-frequency bandgap formation in metastructures. Our efforts on the use of synthetic impedance shunts for programmable piezoelectric metastructures will also be summarized. This talk will conclude with metamaterial-based low-frequency lens and mirror concepts, and band structure tailoring overall, by exploiting LR mechanical and electromechanical unit cells, via bridging the two parts of this presentation.
Biograph:
Dr. Alper Erturk is an Associate Professor & Woodruff Faculty Fellow in the George W. Woodruff School of Mechanical Engineering at Georgia Institute of Technology, where he leads the Smart Structures & Dynamical Systems Laboratory. His research program is centered around the intersection of smart structures and dynamical systems for various interdisciplinary problems ranging from energy harvesting and bio-inspired actuation to acoustic metamaterials and vibration attenuation. He has published around 190 articles in archival journals and conference proceedings, 4 book chapters, and 2 books (total citations ~ 8900 and h-index: 44). Dr. Erturk is a recipient of the NSF CAREER Award (2013) in Dynamical Systems, the 2015 ASME Gary Anderson Early Achievement Award for early career impact in the field of adaptive structures and material systems, and the 2017 ASME C.D. Mote Jr. Early Career Award for demonstrated research excellence in the field of vibration and acoustics. He was also a recipient of the 2015 (inaugural) and 2017 ASME Energy Harvesting Best Paper Awards. Dr. Erturk is an Associate Editor for Smart Materials & Structures (IOP), Journal of Intelligent Material Systems & Structures (SAGE), Journal of Vibration & Acoustics (ASME), and Journal of Energy Engineering (ASCE). He was an Elected Member of the ASME Technical Committee on Vibration & Sound and is currently an Elected Member of the ASME Adaptive Structures & Material Systems Branch. He was also the Founding Chair of the ASME Energy Harvesting Technical Committee. He served on the organization and program committees of various conferences (ASME, SPIE, PowerMEMS, etc.) and is currently the Chair for the 2018 ASME IDETC Mechanical Vibration & Noise Conference and for the 2018 SPIE Smart Structures/NDE - Active & Passive Smart Structures & Integrated Systems Conference. Dr. Erturk received various mentoring and teaching awards, including a Georgia Tech Class of 1940 Teaching Effectiveness Award. He received his PhD in Engineering Mechanics (2009) from Virginia Tech, MS (2006) and BS (2004) from METU (Ankara, Turkey). He is a Fellow of the ASME.