MMAE Seminar - Dr. Gal Shmuel - Universality of the Frequency Spectrum of Laminates
Armour College of Engineering's Mechanical, Materials & Aerospace Engineering Department will welcome Dr. Gal Shmuel, Assistant Professor at the Faculty of Mechanical Engineering, Technion, Israel, on Tuesday, September 6th to present his lecture, Universality of the Frequency Spectrum of Laminates.
Abstract
Waves in periodic media undergo multiple scattering and interference. The corresponding frequency spectrum thus obtains a band structure, being divided to frequency bands in which waves pass without attenuation, and frequency bands in which waves cannot propagate, termed bandgaps. This band structure depends on the physical and geometrical properties of the repetitive cell, through a dispersion equation.
Using a new representation of the dispersion relation of laminates, I will show how their frequency spectrum admits a universal structure. This structure allows to derive the maximal width, the average width, and the density of the bandgaps in the spectrum—the latter found to be independent of the thickness of each constituent and its particular physical properties. Based on these findings, rules for tailoring laminates according to desired spectrum properties follow.
Figure: (Left) Level sets of the dispersion relation over the torus. (Right) The universal structure of the band structure over the flat torus. The density of the bandgaps, denoted in gray, is universal and is calculated analytically over the torus.
Biography
Dr. Gal Shmuel received his Ph.D. in mechanical engineering from Ben-Gurion University in 2012. Thereafter, he was a Postdoctoral associate at the California Institute of Technology. Since 2014, he is an Assistant Professor at the Faculty of Mechanical Engineering, Technion, Israel.
His research is concerned with the mechanics of active materials, which deform and change their properties by application of external stimuli; soft materials, capable of undergoing large deformations; and heterogeneous media, such as composites and polycrystals.