Welcome! I am a 'mechanician', which broadly means someone who studies what happens to objects when load is applied to them. This, however, is a very general description. I work in an interdisciplinary field between mechanical engineering, materials science and applied physics, referred to as 'mechanics of materials'. As a community, we study the fundamental effects of external forces on materials to help improve the performance of technology reliant on these material systems. My current focus lies in understanding structural and multi-functional materials under extreme loading conditions.
Many of these problems are fascinating on account of two general concepts: 1. physical phenomena in materials are non-intuitive when very large and very fast loads are applied; 2. many of these problems involve the interaction of multi-physical phenomena like electromagnetics and chemistry with mechanical fields.
My doctoral research was focused on understanding the response of single and polycrystalline magnesium under fast loading conditions, with applications primarily in the defense sector. Advised by Prof. K. T. Ramesh at the Johns Hopkins University, I focused on studying the dynamics of evolving internal micro-structure and its effects on macroscopic plastic flow within timescales spanning microseconds.
In my current life as a post-doctoral researcher working with Prof. Dennis Kochmann, I am exploring the mechanics of active materials like ferroelectrics (in which mechanical and electrical fields are strongly coupled) and mechanical metamaterials (in which one can design the internal structure of the material to get desired properties like mechanical stiffness, impact resistance, acoustic wave guiding and vibration damping to name a few).
An experimentalist by training, and an amateur theoretician in the making, I believe that meaningful scientific and technological advances require a synergy of the experimental, theoretical and computational sciences from multiple disciplines. More details about my work can be found in the Research page.
Doctor of Philosophy (Ph.D), Mechanical Engineering (2018)
Thesis: Twinning and the dynamic behavior of magnesium and its alloys
Master of Science in Engineering (M.S.E), Mechanical Engineering (2014)
Bachelor of Technology (B.Tech), Production Engineering (2012)
July 22, 2019
Mechanics and Materials
Department of Mechanical and Process Engineering
Tannenstrasse 3, CLA J31
8006 Zürich, Switzerland
Ph: +41 78 639 3707
E-mail: kannanvi@ethz.ch
Skype ID: vigi1991_3
The conventional kolsky bar setup in the Ramesh lab (Latrobe 025) at JHU (Bar diameter: 1/2"). The second image shows the imaging setup modified for high magnification in-situ high speed imaging
In-situ high speed imaging (200 ns temporal resolution) during dynamic compression reveals early occurence of localized instabilities that propagate rapidly across the specimen. Specimen dimension along the direction of compression is ~ 3 mm. Failure occurs after coalescence of localized bands.
Electron backscatter diffraction data of as-received material (from Nick Krywopusk, JHU) and after high strain rate deformation. The colors represent grain orientations (refer to legend in the inset). Significant reorientations of grains observed. Thin bands in post-deformed image are deformation twins which are in the process of reorienting grains by nucleation and growth.
In-situ high speed imaging (200 ns temporal resolution; 5 micron spatial resolution) reveals clues to the dynamics of interacting twins. Notice the two twins in question have correlated velocities as they approach and cross each other. Interaction length scales estimated at 100 microns. Scale bar corresponds to 1 mm.
The desktop kolsky bar in the Ramesh lab at JHU. This setup is used to acheive higher strain rates (a couple of orders of magnitude) than the conventional kolsky bars. The bar diameters are 3mm. The optics on the left of the image are part of a normal displacement interferometer used to measure the back surface displacement on the transmitted bar with high spatial and temporal resolution.
Data recorded from the NDI used with the Desktop Kolsky bar. The inset shows the fringes obtained during the experiment. The number of fringes are directly proportional to the particle displacement. (Spatial resolution 266 nm; Bandwidth: 350 MHz).
We live in an age where anything, anybody says is more easily accessible and hence conveniently misused and misrepresented, quite often with dangerous repercursions. There is no harm in words giving us inspiration as long as we realize they are/were merely a reflection of the authors' attitudes towards their lives and the world as they perceive(d) it. It is this attitude that we really derive inspiration from, and many a time gives us something to ponder upon...
