Antonio Palermo

Antonio Palermo
University of Bologna | UNIBO · Department of Civil, Chemical, Environmental and Materials Engineering DICAM

Doctor of Philosophy

About

63
Publications
15,874
Reads
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1,153
Citations
Citations since 2016
59 Research Items
1143 Citations
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
2016201720182019202020212022050100150200250300
Additional affiliations
February 2017 - July 2017
California Institute of Technology
Position
  • Visiting Research Student
February 2015 - July 2016
ETH Zurich
Position
  • Visiting PhD Student
Education
January 2014 - May 2017
University of Bologna
Field of study
  • Civile Engineering
September 2012 - September 2013
Imperial College London
Field of study
  • Earthquake Engineering
October 2011 - October 2013
University of Bologna
Field of study
  • Civil Engineering

Publications

Publications (63)
Article
In this work, we investigate the dynamic behavior and the topological properties of quasiperiodic elastic metasurfaces, namely arrays of mechanical oscillators arranged over the free surface of a semi-infinite elastic medium according to a quasiperiodic spatial distribution. An ad-hoc multiple scattering formulation is developed to describe the dyn...
Article
We provide an analytical formulation to model the propagation of elastic waves in a homogeneous half-space supporting an array of thin plates. The technique provides the displacement field obtained from the interaction between an incident wave generated by a harmonic source and the scattered fields induced by the flexural motion of the plates. The...
Preprint
Full-text available
In this work, we investigate the dynamic behavior and the topological properties of quasiperiodic elastic metasurfaces, namely arrays of mechanical oscillators arranged over the free surface of an elastic half-space according to a quasiperiodic spatial distribution. An ad-hoc multiple scattering formulation is developed to describe the dynamic inte...
Article
Full-text available
Granular materials can be used in laboratory-scale physical models to simulate and study seismic wave propagation in various unconsolidated, porous heterogeneous media. This is due to the diverse available grain configurations, in terms of their shape, size, and mechanical parameters, which enable the physical and geological modeling of various com...
Article
Love waves are antiplane elastic waves which propagate along the surface of a heterogeneous medium. Under time-harmonic regime, they are governed by a scalar equation of the Helmholtz type. We exploit the invariance of this governing equation under an in-plane arbitrary coordinate transformation to design broadband cloaks for surface defects. In pa...
Preprint
In this work, an unconsolidated granular medium, made of silica microbeads, is experimentally tested in a laboratory setting. The objective is to investigate the attenuation mechanisms of vertically polarized seismic waves traveling at the surface of unconsolidated substrates that are characterized by power-law rigidity profiles. Both geometric spr...
Preprint
In this work, we investigate the dynamics and attenuation properties of a one-dimensional inertial amplified lattice with opposite chirality. The unit cell of the structure consists of a hollow-square plate connected to a ring through arch-like ligaments. The peculiar geometry and orientation of the links allow for coupling the axial and the torsio...
Preprint
Full-text available
We provide an analytical formulation to model the propagation of elastic waves in a homogeneous half-space supporting an array of thin plates. The technique provides the displacement field obtained from the interaction between an incident wave generated by a harmonic source and the scattered fields induced by the flexural motion of the plates. The...
Article
Metamaterials with microscale architectures, e.g., microlattices, can exhibit extreme quasi-static mechanical response and tailorable acoustic properties. When coupled with pressure waves in surrounding fluid, the dynamic behavior of microlattices in the long wavelength limit can be explained in the context of Biot’s theory of poroelasticity. In th...
Preprint
Full-text available
Love waves are antiplane elastic waves which propagate along the surface of a heterogeneous medium. Under time-harmonic regime, they are governed by a scalar equation of the Helmholtz type. We exploit the invariance of this governing equation under an in-plane arbitrary coordinate transformation to design broadband cloaks for surface defects. In pa...
Preprint
Full-text available
In this work, we experimentally and numerically investigate the propagation and attenuation of vertically polarized surface waves in an unconsolidated granular medium equipped with small-scale metabarriers of different depths, i.e., arrays composed of one, two, and three embedded layers of sub-wavelength resonators. Our findings reveal how such a m...
Article
We propose an analytical framework to model the effect of single and multiple mechanical surface oscillators on the dynamics of vertically polarized elastic waves propagating in a half-space. The formulation extends the canonical Lamb’s problem, originally developed to obtain the wavefield induced by a harmonic line source in an elastic half-space....
Preprint
We investigate the propagation of Rayleigh waves in a half-space coupled to a nonlinear metasurface. The metasurface consists of an array of nonlinear oscillators attached to the free surface of a homogeneous substrate. We describe, analytically and numerically, the effects of nonlinear interaction force and energy loss on the dispersion of Rayleig...
Article
We investigate the propagation of Rayleigh waves in a half-space coupled to a nonlinear metasurface. The metasurface consists of an array of nonlinear oscillators attached to the free surface of a homogeneous substrate. We describe, analytically and numerically, the effects of nonlinear interaction force and energy loss on the dispersion of Rayleig...
Preprint
Full-text available
We propose an analytical framework to model the effect of single and multiple mechanical surface oscillators on the dynamics of vertically polarized elastic waves propagating in a semi-infinite medium. The formulation extends the canonical Lamb's problem, originally developed to obtain the wavefield induced by a harmonic line source in an elastic h...
Article
Full-text available
In this work, we experimentally and numerically investigate the propagation and attenuation of vertically polarized surface waves in an unconsolidated granular medium equipped with small-scale metabarriers of different depths, i.e., arrays composed of one, two, and three embedded layers of sub-wavelength resonators. Our findings reveal how such a m...
Article
The design of metamaterials for surface waves control is an emerging field of research which can impact several technical applications, from electronic devices based on surface acoustic waves (SAW) to wave barriers for seismic isolation. So far, studies on the interaction of surface waves with locally resonant metamaterials have been limited to the...
Article
In this work, we design an experimental campaign to assess the attenuation performance of a medium-scale resonant wave barrier operating within the frequency range of 50–100 Hz. In particular, the dispersive properties of (i) bare soil, (ii) a configuration of “dead masses” placed over the soil surface, and (iii) a locally resonant barrier, also kn...
Article
We investigate how Rayleigh waves interact with modulated resonators located on the free surface of a semi-infinite elastic medium. We begin by studying the dynamics of a single resonator with time-modulated stiffness, we evaluate the accuracy of an analytical approximation of the resonator response and identify the parameter ranges in which its be...
Article
Seismic surface wave mitigation using metamaterials is a growing research field propelled by intrinsic theoretical value and possible application prospects. Up to date, the complexity of site conditions found in engineering practice, which can include layered stratigraphy and variable water table level, has been discarded in the development of anal...
Preprint
Full-text available
We investigate how Rayleigh waves interact with modulated resonators located on the free surface of a semi-infinite elastic medium. We begin by studying the dynamics of a single resonator with time-modulated stiffness. In particular, we evaluate the accuracy of an analytical approximation of the resonator response and identify the parameter ranges...
Article
The article analyses two potential metamaterial designs, the metafoundation and the metabarrier, capable to attenuate seismic waves impact on buildings or structural components in a frequency band between 3.5 and 8 Hz. The metafoundation serves the dual purpose of reducing the seismic response and supporting the superstructure. Conversely the metab...
Preprint
Full-text available
Haptic feedback is the most significant sensory interface following visual cues. Developing thin, flexible surfaces that function as haptic interfaces is important for augmenting virtual reality, wearable devices, robotics and prostheses. For example, adding a haptic feedback interface to prosthesis could improve their acceptance among amputees. St...
Article
This paper proposes a novel inertial-amplification-mechanism (IAM) to enhance the vibration mitigation performance of the classical tuned-mass-damper (TMD). To this aim, the IAM is coupled to a standard TMD to form a so-called IAM-TMD. Analytical derivations are developed to extend the theory of the classical TMD to the IAM-TMD. Next, $H_\infty$ an...
Article
Full-text available
Haptic feedback is the most significant sensory interface following visual cues. Developing thin, flexible surfaces that function as haptic interfaces is important for augmenting virtual reality, wearable devices, robotics and prostheses. For example, adding a haptic feedback interface to prosthesis could improve their acceptance among amputees. St...
Article
In recent years, a new type of seismic isolation system which exploits the filtering effect of bandgaps, named Periodic Foundation, has been proposed to isolate the upper structure from ground motion. To date, several works have been conducted to validate the feasibility and efficiency of this new isolation system. However, these works focused on t...
Article
Full-text available
In this paper, the physics of horizontally polarized shear waves traveling across a locally resonant metasurface in an unconsolidated granular medium is experimentally and numerically explored. The metasurface is comprised of an arrangement of subwavelength horizontal mechanical resonators embedded in a granular layer made of silica microbeads. The...
Preprint
Full-text available
In order to find the experimental band structure of a mass-in-mass lattice, we developed an experimental procedure and provided the indicators needed to validate the results. The behaviour of a large scale single unit-cell under Floquet-Bloch boundary conditions is analysed. Such an experiment has never been carried out before on a large scale test...
Conference Paper
Full-text available
The growing interest about meta-structures from the civil engineer community has led to the development of novel low frequency isolation systems for ground borne vibrations and seismic waves. Among those, the resonant Metabarrier, i.e., an array of meter-size resonators embedded in the ground around the structure, or a cluster of structures, to be...
Preprint
Full-text available
In this article the physics of horizontally polarized shear waves travelling across a locally resonant metasurface in an unconsolidated granular medium is experimentally and numerically explored. The metasurface is comprised of an arrangement of sub-wavelength horizontal mechanical resonators embedded in silica microbeads. The metasurface supports...
Article
This article presents an efficient reduced formulation of the Bloch Operator Finite Element method to calculate complex band structures of periodic waveguides. The use of a Bloch operator formulation allows building and solving a Bloch eigenvalue problem along a generic wave direction, thus being not limited to the unit cell Irreducible Brillouin Z...
Conference Paper
We present a tabletop-scale realization of a tunable metamaterial platform to control surface acoustic waves (SAWs). The platform comprises an array of ferromagnetic beads controlled with permanent magnets, arranged atop an elastic substrate. We demonstrate the possibility of shifting the beads resonances and, in turn, tuning the SAWs bandgaps.
Preprint
Full-text available
The article analyses two potential metamaterial designs, the metafoundation and the metabarrier, capable to attenuate seismic waves on buildings or structural components in a frequency band between 3.5 to 8 Hz. The metafoundation serves the dual purpose of reducing the seismic response and supporting the superstructure. Conversely the metabarrier s...
Article
In this work, we propose an inertial amplified resonator (IAR) as a building block of a tunable locally resonant metasurface. The IAR consists in a mass–spring resonator coupled with two inerters, realized by two inclined rigid links connected to an additional mass. The IAR has a static behaviour equivalent to that of a standard mass–spring oscilla...
Presentation
Arrays of mechanical resonators, referred to as metasurfaces, have proven capable of controlling in-plane polarized surface waves across multiple length scales, i.e., from the micrometer scale, for the design of devices for sensing applications, up to the metric scale, for the attenuation of mechanical and seismic vibrations. In the context of seis...
Article
In this work, we propose the use of contact resonances, controlled via an external magnetic field, as a tunable platform to manipulate the dispersion of surface acoustic waves (SAWs). We exploit the analogy between surface acoustic waves in a semi-infinite medium and edge waves in a plate, to realize a compact experimental setup and to demonstrate...
Article
Artificial soils engineered with periodic or resonant structures, also referred as “seismic metamaterials” have been investigated for earthquake mitigation applications. In particular, an array of sub-wavelength single-mass resonators buried close the soil surface, namely the metabarrier, has been recently proposed to attenuate the ground motion in...
Conference Paper
Arrays of surface resonators forming so-called metabarriers are capable of converting seismic Rayleigh waves into less dangerous shear waves traveling in the bulk, attenuating the ground motion at the surface. However, this phenomenon pertains to resonant materials inserted in homogeneous media which feature properties rather different to those of...
Article
Full-text available
Microlattices are architected materials that allow for an unprecedented control of mechanical properties (e.g., stiffness, density, and Poisson's coefficient). In contrast to their quasi-static mechanical properties, the acoustic properties of microlattices remain largely unexplored. This paper analyzes the acoustic response of periodic millimeter-...
Conference Paper
Full-text available
Metasurfaces, consisting in an array of resonant inclusions or resonant elements placed at a waveguide free surface, can be designed to interact with elastic waves and used to redirect, steer or absorb the elastic wave energy. Metasurfaces in half spaces are capable to support the propagation of shear horizontally polarized waves and to open band g...
Article
Full-text available
We investigate the interaction of guided surface acoustic modes (GSAMs) in unconsolidated granular media with a metasurface, consisting of an array of vertical oscillators. We experimentally observe the hybridization of the lowest-order GSAM at the metasurface resonance, and note the absence of mode delocalization found in homogeneous media. Our nu...
Article
Full-text available
Metasurfaces of mechanical resonators have been successfully used to control in-plane polarized surface waves for filtering, waveguiding and lensing applications across different length scales. In this work, we extend the concept of metasurfaces to anti-plane surface waves existing in semi-infinite layered media, generally known as Love waves. By m...
Article
Full-text available
Identifying material geometries that lead to metamaterials with desired functionalities presents a challenge for the field. Discrete, or reduced-order, models provide a concise description of complex phenomena, such as negative refraction, or topological surface states; therefore, the combination of geometric building blocks to replicate discrete m...
Article
Elastic metamaterials are artificial composites with subwavelength resonant particles hosted in a medium able to manipulate the propagation of elastic waves. When the resonant particles are placed at the free surface of the medium to form a resonant “metasurface,” the localization mechanism and the direction of surface waves can be fully controlled...
Article
Mass-spring models provide a straightforward way to describe complex dynamic behavior of mechanical systems, such as topologically protected and backscattering-free surface phonons. Such discrete models also provide a means to translate these properties, based on the unique class of electronic materials of topological insulators, to the mechanical...
Presentation
The advent of metamaterials, artificial composite structures engineered with unusual features not found in nature, has encouraged the development of numerous applications for the control of wave propagation in different fields, from electromagnetics to acoustics, and more recently up to the seismic protection domain. Especially after the developmen...
Article
Full-text available
Resonant metamaterials have been proposed to reflect or redirect elastic waves at different length scales, ranging from thermal vibrations to seismic excitation. However, for seismic excitation, where energy is mostly carried by surface waves, energy reflection and redirection might lead to harming surrounding regions. Here, we propose a seismic me...
Article
Discrete models provide concise descriptions of complex physical phenomena, such as negative refraction, topological insulators, and Anderson localization. While there are multiple tools to obtain discrete models that demonstrate particular phenomena, it remains a challenge to find metamaterial designs that replicate the behavior of desired nontriv...
Article
In this article an efficient numerical technique, named Extended Bloch Mode Synthesis, is proposed for the fast calculation of the elastic complex band structures in phononic media. The Bloch Mode Synthesis approach, originally developed for reducing the computational cost for the calculation of real band structures, is here extended to evaluate al...
Article
Full-text available
In this study waves propagating in a diatomic linear viscoelastic periodic system are investigated with the aim of understanding the operative range of some commonly adopted rheological models. Dispersion laws of a diatomic viscoelastic periodic system under prescribed harmonic motion, i.e. real angular frequency and complex wavenumber (wavenumber...
Article
Full-text available
Architected materials that control elastic wave propagation are essential in vibration mitigation and sound attenuation. Phononic crystals and acoustic metamaterials use band gap engineering to forbid certain frequencies from propagating through a material. However, existing solutions are limited in the low frequency regimes and in their bandwidth...
Article
In this study, the effect of energy dissipation on harmonic waves propagating in one-dimensional monoatomic linear viscoelastic mass-spring chains is investigated. In particular, first dispersion laws in terms of wavenumber, attenuation, and wave propagation velocities (phase, group, and energy) for a generic viscoelastic mass-spring chain are deri...
Article
Full-text available
A simple beam model for the evaluation of tile debonding due to substrate shrinkage is presented. The tile-adhesive-substrate package is modeled as an Euler-Bernoulli beam laying on a two-layer elastic foundation. An effective discrete model for inter-tile grouting is introduced with the aim of modelling workmanship defects due to partial filled gr...

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Project (1)
Project
We invite you to submit a contribution for the MS on “Mechanical metamaterials for waves mitigation and control” (MS#54), organized for the Engineering Mechanics Institute Conference 2019 (EMI 2019). EMI 2019 is taking place on June 18-June 21, 2019, at Caltech. Metamaterials consist of a special class of media or structures characterized by passive filtering properties: when the frequency of the incoming waves falls into their “blind” zone, their propagation is mitigated or even arrested, forming thus a “band-gap”. These band gaps have allowed obtaining materials for low-frequency (albeit narrow) wave steering or devices for optical and acoustic cloaking. Inspired from the fields of optics and acoustics, the use of metamaterials for the attenuation of structural and mechanical vibrations is increasingly attracting the interest of scientists and engineers. The aim of this mini-symposium (MS) is to present and discuss the recent advances in the field, ranging from purely theoretical investigations, to numerical simulations and experimental case studies. MS topics include, among others: theoretical background, dispersion analysis of infinite lattices, performance of finite lattices, wave filtering, scattering and mode conversion, soil-structure interaction, nonlinear and uncertain metamaterials, design and optimizations. Applications in structural dynamics, earthquake engineering, geotechnical engineering, as well as mechanical and aerospace engineering are welcomed, while papers covering experimental investigations in both laboratory tests and free field are particularly appreciated. Further details for the conference can be found at http://emi2019.caltech.edu/ The deadline for submission of abstracts is January 30, 2019. Minisymposium Organizers: Vasilis Dertimanis, ETH Zurich Antonio Palermo, California Institute of Technology Domniki Asimaki, California Institute of Technology Eleni Chatzi, ETH Zurich Alessandro Marzani, University of Bologna Chiara Daraio, California Institute of Technology