The Experts below are selected from a list of 3339 Experts worldwide ranked by ideXlab platform
Chiara Daraio - One of the best experts on this subject based on the ideXlab platform.
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solitary wave based delamination detection in composite plates using a combined Granular Crystal sensor and actuator
Smart Materials and Structures, 2015Co-Authors: Eunho Kim, Francesco Restuccia, Jinkyu Yang, Chiara DaraioAbstract:We experimentally and numerically investigate a diagnostic method for detecting hidden delamination in composite panels, using highly nonlinear solitary waves. Solitary waves are a type of nonlinear waves with strong energy intensity and non-distortive nature, which can be controllably generated in one-dimensional Granular Crystals. In this study, we use Granular Crystals as a combined sensor and actuator to detect hidden delamination in carbon fiber reinforced polymer (CFRP) composite panels. Specifically, we locally excite a CFRP composite specimen using the Granular Crystal as an actuator and measure the reflected waves that carry the specimen's diagnostic information using the same device as a sensor. We first investigate the effect of the panel's boundary conditions on the response of the reflected solitary waves. We then investigate the interactions of a solitary wave with delamination hidden in the CFRP composite specimen. Lastly, we define a damage index based on the solitary waves' responses to identify the location of the hidden delamination in the CFRP composite panel. The solitary wave-based diagnostic method can provide unique merits, such as portable and fast sensing of composites' hidden damage, thereby with the potential of being used for hot spot monitoring of composite-based structures.
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local to extended transitions of resonant defect modes
Physical Review Letters, 2014Co-Authors: Joseph Lydon, Marc Serragarcia, Chiara DaraioAbstract:We study the localized modes created by introducing a resonant defect in a mechanical lattice. We find that modes introduced by resonant defects have profiles that can be tuned from being extremely localized to totally delocalized by an external force. This is in direct contrast with modes introduced by traditional mass or stiffness defects, in which the modes’ profiles stay constant. We present an analytical model for resonant defects in one-dimensional nonlinear lattices, computationally demonstrate the equivalent effect in a two-dimensional lattice, and experimentally observe the mode profiles in a Granular Crystal. While our study is concerned with nonlinear mechanical lattices, the generality of our model suggests that the same effect should be present in other types of periodic lattices.
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traveling waves in 2d hexagonal Granular Crystal lattices
Granular Matter, 2014Co-Authors: Andrea Leonard, C Chong, P G Kevrekidis, Chiara DaraioAbstract:This study describes the dynamic response of a two-dimensional hexagonal packing of uncompressed stainless steel spheres excited by localized impulsive loadings. The dynamics of the system are modeled using the Hertzian normal contact law. After the initial impact strikes the system, a characteristic wave structure emerges and continuously decays as it propagates through the lattice. Using an extension of the binary collision approximation for one-dimensional chains, we predict its decay rate, which compares well with numerical simulations and experimental data. While the hexagonal lattice does not support constant speed traveling waves, we provide scaling relations that characterize the directional power law decay of the wave velocity for various angles of impact. Lastly, we discuss the effects of weak disorder on the directional amplitude decay rates.
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traveling waves in 2d hexagonal Granular Crystal lattices
arXiv: Pattern Formation and Solitons, 2013Co-Authors: Andrea Leonard, C Chong, P G Kevrekidis, Chiara DaraioAbstract:We describe the dynamic response of a two-dimensional hexagonal packing of uncompressed stainless steel spheres excited by localized impulsive loadings. After the initial impact strikes the system, a characteristic wave structure emerges and continuously decays as it propagates through the lattice. Using an extension of the binary collision approximation (BCA) for one-dimensional chains, we predict its decay rate, which compares well with numerical simulations and experimental data. While the hexagonal lattice does not support constant speed traveling waves, we provide scaling relations that characterize the power law decay of the wave velocity. Lastly, we discuss the effects of weak disorder on the directional amplitude decay rates.
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monitoring the hydration of cement using highly nonlinear solitary waves
Ndt & E International, 2012Co-Authors: Piervincenzo Rizzo, Jinkyu Yang, Devvrath Katri, Chiara DaraioAbstract:In this paper we present a nondestructive evaluation technique based on the propagation of highly nonlinear solitary waves (HNSWs) to monitor the hydration of cement. HNSWs are mechanical waves that can form and travel in highly nonlinear systems, such as one-dimensional chains of contacting spherical particles (i.e., Granular Crystals). In the present study, we use a Granular Crystal-based actuator/sensor to observe the solitary waves propagating to and from the mechanical interface between the transducer and a fresh gypsum cement sample. We hypothesize that the reflected HNSWs traveling along the Crystal-based transducer are affected by the hydration process of the cement, and we assess the elastic modulus of the specimen in the localized region of the Granular Crystal contact. To verify the experimental results, we perform numerical simulations based on a simplified finite element model. The elastic properties of the cement specimen measured by the Granular Crystal transducer are compared with the compressive strength and the elastic modulus measurements obtained from destructive tests, conducted according to the ASTM C109. We observe good agreement between experiments and numerical simulations.
Jinkyu Yang - One of the best experts on this subject based on the ideXlab platform.
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solitary wave based delamination detection in composite plates using a combined Granular Crystal sensor and actuator
Smart Materials and Structures, 2015Co-Authors: Eunho Kim, Francesco Restuccia, Jinkyu Yang, Chiara DaraioAbstract:We experimentally and numerically investigate a diagnostic method for detecting hidden delamination in composite panels, using highly nonlinear solitary waves. Solitary waves are a type of nonlinear waves with strong energy intensity and non-distortive nature, which can be controllably generated in one-dimensional Granular Crystals. In this study, we use Granular Crystals as a combined sensor and actuator to detect hidden delamination in carbon fiber reinforced polymer (CFRP) composite panels. Specifically, we locally excite a CFRP composite specimen using the Granular Crystal as an actuator and measure the reflected waves that carry the specimen's diagnostic information using the same device as a sensor. We first investigate the effect of the panel's boundary conditions on the response of the reflected solitary waves. We then investigate the interactions of a solitary wave with delamination hidden in the CFRP composite specimen. Lastly, we define a damage index based on the solitary waves' responses to identify the location of the hidden delamination in the CFRP composite panel. The solitary wave-based diagnostic method can provide unique merits, such as portable and fast sensing of composites' hidden damage, thereby with the potential of being used for hot spot monitoring of composite-based structures.
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impact identification in sandwich structures using solitary wave supporting Granular Crystal sensors
AIAA Journal, 2014Co-Authors: Amit Shelke, Ahsan Uddin, Jinkyu YangAbstract:A new diagnostic method to identify the location and magnitude of external impact on a sandwich structure using Granular Crystal sensors was studied. The Granular Crystal sensors are composed of one-dimensional chains of spherical particles that are inserted in a thick core of the sandwich structure. Given an external impact, the embedded sensors generate compact-supported, highly nonlinear solitary waves resulting from the dispersive and nonlinear characteristics of Granular Crystals. In this study, the propagating mechanism of highly nonlinear solitary waves in relation to various impact conditions was investigated. Particularly, it was reported that the flight time and magnitude of solitary waves are highly sensitive to the location and amplitude of impact. By analyzing measured solitary waves, the striker’s impact location and drop height was successfully predicted nondestructively. It was found that the diagnostic results are in agreement with the numerical simulations obtained from a combined spectr...
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attenuation of solitary waves and localization of breathers in 1d Granular Crystals visualized via high speed photography
Experimental Mechanics, 2014Co-Authors: Jinkyu Yang, Marcial Gonzalez, Eunho Kim, C Agbasi, Michael A SuttonAbstract:We investigate the propagation, attenuation, and localization of nonlinear elastic waves in a 1D Granular Crystal using high speed photography. We measure temporal displacement profiles of individual particles with a micrometer-scale resolution, and we reconstruct force profiles of propagating solitary waves and localized breathers by synchronizing and analyzing the acquired data. These investigations provide quantitative evidence for the transmission and attenuation trends of travelling solitary waves in a soft polymeric chain, which are significantly different from those in a hard metallic chain. We additionally study energy localization in a chain of hard particles embedded with a soft polymeric impurity. Specifically, we show that the proposed experimental technique is able to visualize the formation of localized breathers and quantify the energy highly concentrated in the vicinity of the impurity site—a phenomenon which can be exploited for harvesting vibrational energy in engineering applications. Finally, we compare, with good agreement, the experimental results with discrete element numerical simulations that account for dissipative effects due to viscoelasticity. The findings reported in this study imply that high speed photography can be an efficient and effective tool for non-contact measurements of nonlinear wave dynamics in Granular lattices, despite their short characteristic times and minute displacements.
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monitoring the hydration of cement using highly nonlinear solitary waves
Ndt & E International, 2012Co-Authors: Piervincenzo Rizzo, Jinkyu Yang, Devvrath Katri, Chiara DaraioAbstract:In this paper we present a nondestructive evaluation technique based on the propagation of highly nonlinear solitary waves (HNSWs) to monitor the hydration of cement. HNSWs are mechanical waves that can form and travel in highly nonlinear systems, such as one-dimensional chains of contacting spherical particles (i.e., Granular Crystals). In the present study, we use a Granular Crystal-based actuator/sensor to observe the solitary waves propagating to and from the mechanical interface between the transducer and a fresh gypsum cement sample. We hypothesize that the reflected HNSWs traveling along the Crystal-based transducer are affected by the hydration process of the cement, and we assess the elastic modulus of the specimen in the localized region of the Granular Crystal contact. To verify the experimental results, we perform numerical simulations based on a simplified finite element model. The elastic properties of the cement specimen measured by the Granular Crystal transducer are compared with the compressive strength and the elastic modulus measurements obtained from destructive tests, conducted according to the ASTM C109. We observe good agreement between experiments and numerical simulations.
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mesoscopic approach to Granular Crystal dynamics
Physical Review E, 2012Co-Authors: Marcial Gonzalez, Chiara Daraio, Jinkyu Yang, M OrtizAbstract:We present a mesoscopic approach to Granular Crystal dynamics, which comprises a three-dimensional finite-element model and a one-dimensional regularized contact model. The approach investigates the role of vibrational-energy trapping effects in the dynamic behavior of one-dimensional chains of particles in contact (i.e., Granular Crystals), under small to moderate impact velocities. The only inputs of the models are the geometry and the elastic material properties of the individual particles that form the system. We present detailed verification results and validate the model comparing its predictions with experimental data. This approach provides a physically sound, first-principle description of dissipative losses in Granular systems.
Nicholas Boechler - One of the best experts on this subject based on the ideXlab platform.
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shear to longitudinal mode conversion via second harmonic generation in a two dimensional microscale Granular Crystal
Wave Motion, 2017Co-Authors: Samuel P Wallen, Nicholas BoechlerAbstract:Abstract Shear to longitudinal mode conversion via second harmonic generation is studied theoretically and computationally for plane waves in a two-dimensional, adhesive, hexagonally close-packed microscale Granular medium. The model includes translational and rotational degrees of freedom, as well as normal and shear contact interactions. We consider fundamental frequency plane waves in all three linear modes, which have infinite spatial extent and travel in one of the high-symmetry Crystal directions. The generated second harmonic waves are longitudinal for all cases. For the lower transverse–rotational mode, an analytical expression for the second harmonic amplitude, which is derived using a successive approximations approach, reveals the presence of particular resonant and antiresonant wave numbers, the latter of which is prohibited if rotations are not included in the model. By simulating a lattice with adhesive contact force laws, we study the effectiveness of the theoretical analysis for non-resonant, resonant, and antiresonant cases. This work is suitable for the analysis of microscale and statically compressed macroscale Granular media, and should inspire future studies on nonlinear two- and three-dimensional Granular systems in which interparticle shear coupling and particle rotations play a significant role.
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Spatial Laplace transform for complex wavenumber recovery and its application to the analysis of attenuation in acoustic systems
Journal of Applied Physics, 2016Co-Authors: A. Geslain, Nicholas Boechler, Samuel Raetz, M. Hiraiwa, M. Abi Ghanem, P. Wallen, A. Khanolkar, J. Laurent, C. Prada, Aroune DuclosAbstract:We present a method for the recovery of complex wavenumber information via spatial Laplace transforms of spatiotemporal wave propagation measurements. The method aids in the analysis of acoustic attenuation phenomena and is applied in three different scenarios: (i) Lamb-like modes in air-saturated porous materials in the low kHz regime, where the method enables the recovery of viscoelastic parameters; (ii) Lamb modes in a Duralumin plate in the MHz regime, where the method demonstrates the effect of leakage on the splitting of the forward S-1 and backward S-2 modes around the Zero-Group Velocity point; and (iii) surface acoustic waves in a two-dimensional microscale Granular Crystal adhered to a substrate near 100 MHz, where the method reveals the complex wave-numbers for an out-of-plane translational and two in-plane translational-rotational resonances. This method provides physical insight into each system and serves as a unique tool for analyzing spatiotemporal measurements of propagating waves.
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complex contact based dynamics of microsphere monolayers revealed by resonant attenuation of surface acoustic waves
Physical Review Letters, 2016Co-Authors: Morgan Hiraiwa, Alexei A. Maznev, A. Khanolkar, Samuel P Wallen, Abi M Ghanem, Nicholas BoechlerAbstract:Contact-based vibrations play an essential role in the dynamics of Granular materials. Significant insights into vibrational Granular dynamics have previously been obtained with reduced-dimensional systems containing macroscale particles. We study contact-based vibrations of a two-dimensional monolayer of micron-sized spheres on a solid substrate that forms a microscale Granular Crystal. Measurements of the resonant attenuation of laser-generated surface acoustic waves reveal three collective vibrational modes that involve displacements and rotations of the microspheres, as well as interparticle and particle-substrate interactions. To identify the modes, we tune the interparticle stiffness, which shifts the frequency of the horizontal-rotational resonances while leaving the vertical resonance unaffected. From the measured contact resonance frequencies we determine both particle-substrate and interparticle contact stiffnesses and find that the former is an order of magnitude larger than the latter. This study paves the way for investigating complex contact-based dynamics of microscale Granular Crystals and yields a new approach to studying micro- to nanoscale contact mechanics in multiparticle networks.
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interaction of a contact resonance of microspheres with surface acoustic waves
Physical Review Letters, 2013Co-Authors: Nicholas Boechler, J. K. Eliason, Alexei A. Maznev, K.a. Nelson, Anshuman Kumar, Nicholas X FangAbstract:We study the interaction of surface acoustic waves (SAWs) with a contact-based vibrational resonance of 1 μm silica microspheres forming a two-dimensional Granular Crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit "avoided crossing" behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale Granular Crystals.
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interaction of a contact resonance of microspheres with surface acoustic waves
Physical Review Letters, 2013Co-Authors: Nicholas Boechler, J. K. Eliason, Alexei A. Maznev, K.a. Nelson, Anshuman Kumar, Nicholas X FangAbstract:We study the interaction of surface acoustic waves (SAWs) with a contact-based vibrational resonance of $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ silica microspheres forming a two-dimensional Granular Crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit ``avoided crossing'' behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale Granular Crystals.
Alexei A. Maznev - One of the best experts on this subject based on the ideXlab platform.
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complex contact based dynamics of microsphere monolayers revealed by resonant attenuation of surface acoustic waves
Physical Review Letters, 2016Co-Authors: Morgan Hiraiwa, Alexei A. Maznev, A. Khanolkar, Samuel P Wallen, Abi M Ghanem, Nicholas BoechlerAbstract:Contact-based vibrations play an essential role in the dynamics of Granular materials. Significant insights into vibrational Granular dynamics have previously been obtained with reduced-dimensional systems containing macroscale particles. We study contact-based vibrations of a two-dimensional monolayer of micron-sized spheres on a solid substrate that forms a microscale Granular Crystal. Measurements of the resonant attenuation of laser-generated surface acoustic waves reveal three collective vibrational modes that involve displacements and rotations of the microspheres, as well as interparticle and particle-substrate interactions. To identify the modes, we tune the interparticle stiffness, which shifts the frequency of the horizontal-rotational resonances while leaving the vertical resonance unaffected. From the measured contact resonance frequencies we determine both particle-substrate and interparticle contact stiffnesses and find that the former is an order of magnitude larger than the latter. This study paves the way for investigating complex contact-based dynamics of microscale Granular Crystals and yields a new approach to studying micro- to nanoscale contact mechanics in multiparticle networks.
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interaction of a contact resonance of microspheres with surface acoustic waves
Physical Review Letters, 2013Co-Authors: Nicholas Boechler, J. K. Eliason, Alexei A. Maznev, K.a. Nelson, Anshuman Kumar, Nicholas X FangAbstract:We study the interaction of surface acoustic waves (SAWs) with a contact-based vibrational resonance of $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ silica microspheres forming a two-dimensional Granular Crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit ``avoided crossing'' behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale Granular Crystals.
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interaction of a contact resonance of microspheres with surface acoustic waves
Physical Review Letters, 2013Co-Authors: Nicholas Boechler, J. K. Eliason, Alexei A. Maznev, K.a. Nelson, Anshuman Kumar, Nicholas X FangAbstract:We study the interaction of surface acoustic waves (SAWs) with a contact-based vibrational resonance of 1 μm silica microspheres forming a two-dimensional Granular Crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit "avoided crossing" behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale Granular Crystals.
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Interaction of a contact resonance of microspheres with surface acoustic waves
Physical Review Letters, 2013Co-Authors: Nicholas Boechler, J. K. Eliason, Alexei A. Maznev, K.a. Nelson, Ashwani Kumar, N. FangAbstract:We study the interaction of surface acoustic waves (SAWs) with the contact-based, axial vibrational resonance of 1 \mu m silica microspheres forming a two-dimensional Granular Crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit "avoided crossing" behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model, and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale Granular Crystals.
Nicholas X Fang - One of the best experts on this subject based on the ideXlab platform.
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interaction of a contact resonance of microspheres with surface acoustic waves
Physical Review Letters, 2013Co-Authors: Nicholas Boechler, J. K. Eliason, Alexei A. Maznev, K.a. Nelson, Anshuman Kumar, Nicholas X FangAbstract:We study the interaction of surface acoustic waves (SAWs) with a contact-based vibrational resonance of 1 μm silica microspheres forming a two-dimensional Granular Crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit "avoided crossing" behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale Granular Crystals.
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interaction of a contact resonance of microspheres with surface acoustic waves
Physical Review Letters, 2013Co-Authors: Nicholas Boechler, J. K. Eliason, Alexei A. Maznev, K.a. Nelson, Anshuman Kumar, Nicholas X FangAbstract:We study the interaction of surface acoustic waves (SAWs) with a contact-based vibrational resonance of $1\text{ }\text{ }\ensuremath{\mu}\mathrm{m}$ silica microspheres forming a two-dimensional Granular Crystal adhered to a substrate. The laser-induced transient grating technique is used to excite SAWs and measure their dispersion. The measured dispersion curves exhibit ``avoided crossing'' behavior due to the hybridization of the SAWs with the microsphere resonance. We compare the measured dispersion curves with those predicted by our analytical model and find excellent agreement. The approach presented can be used to study the contact mechanics and adhesion of micro- and nanoparticles as well as the dynamics of microscale Granular Crystals.
