The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Sourav Banerjee - One of the best experts on this subject based on the ideXlab platform.
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experimental verification and validation of nonlocal peridynamic approach for simulating guided lamb wave propagation and damage interaction
Structural Health Monitoring-an International Journal, 2019Co-Authors: Subir Patra, Hossain Ahmed, Mohammadsadegh Saadatzi, Sourav BanerjeeAbstract:In this article, experimental verification and validation of a peridynamics-based simulation technique, called peri-Elastodynamics, are presented while simulating the guided Lamb wave propagation a...
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Peri-Elastodynamic Simulations of Guided Ultrasonic Waves in Plate-Like Structure with Surface Mounted PZT
Sensors, 2018Co-Authors: Subir Patra, Hossain Ahmed, Sourav BanerjeeAbstract:Peridynamic based elastodynamic computation tool named Peri-Elastodynamics is proposed herein to simulate the three-dimensional (3D) Lamb wave modes in materials for the first time. Peri-Elastodynamics is a nonlocal meshless approach which is a scale-independent generalized technique to visualize the acoustic and ultrasonic waves in plate-like structure, micro-electro-mechanical systems (MEMS) and nanodevices for their respective characterization. In this article, the characteristics of the fundamental Lamb wave modes are simulated in a sample plate-like structure. Lamb wave modes are generated using a surface mounted piezoelectric (PZT) transducer which is actuated from the top surface. The proposed generalized Peri-Elastodynamics method is not only capable of simulating two dimensional (2D) in plane wave under plane strain condition formulated previously but also capable of accurately simulating the out of plane Symmetric and Antisymmetric Lamb wave modes in plate like structures in 3D. For structural health monitoring (SHM) of plate-like structures and nondestructive evaluation (NDE) of MEMS devices, it is necessary to simulate the 3D wave-damage interaction scenarios and visualize the different wave features due to damages. Hence, in addition, to simulating the guided ultrasonic wave modes in pristine material, Lamb waves were also simulated in a damaged plate. The accuracy of the proposed technique is verified by comparing the modes generated in the plate and the mode shapes across the thickness of the plate with theoretical wave analysis.
Subir Patra - One of the best experts on this subject based on the ideXlab platform.
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experimental verification and validation of nonlocal peridynamic approach for simulating guided lamb wave propagation and damage interaction
Structural Health Monitoring-an International Journal, 2019Co-Authors: Subir Patra, Hossain Ahmed, Mohammadsadegh Saadatzi, Sourav BanerjeeAbstract:In this article, experimental verification and validation of a peridynamics-based simulation technique, called peri-Elastodynamics, are presented while simulating the guided Lamb wave propagation a...
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Peri-Elastodynamic Simulations of Guided Ultrasonic Waves in Plate-Like Structure with Surface Mounted PZT
Sensors, 2018Co-Authors: Subir Patra, Hossain Ahmed, Sourav BanerjeeAbstract:Peridynamic based elastodynamic computation tool named Peri-Elastodynamics is proposed herein to simulate the three-dimensional (3D) Lamb wave modes in materials for the first time. Peri-Elastodynamics is a nonlocal meshless approach which is a scale-independent generalized technique to visualize the acoustic and ultrasonic waves in plate-like structure, micro-electro-mechanical systems (MEMS) and nanodevices for their respective characterization. In this article, the characteristics of the fundamental Lamb wave modes are simulated in a sample plate-like structure. Lamb wave modes are generated using a surface mounted piezoelectric (PZT) transducer which is actuated from the top surface. The proposed generalized Peri-Elastodynamics method is not only capable of simulating two dimensional (2D) in plane wave under plane strain condition formulated previously but also capable of accurately simulating the out of plane Symmetric and Antisymmetric Lamb wave modes in plate like structures in 3D. For structural health monitoring (SHM) of plate-like structures and nondestructive evaluation (NDE) of MEMS devices, it is necessary to simulate the 3D wave-damage interaction scenarios and visualize the different wave features due to damages. Hence, in addition, to simulating the guided ultrasonic wave modes in pristine material, Lamb waves were also simulated in a damaged plate. The accuracy of the proposed technique is verified by comparing the modes generated in the plate and the mode shapes across the thickness of the plate with theoretical wave analysis.
Jurg Dual - One of the best experts on this subject based on the ideXlab platform.
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elastodynamic wave propagation in graded materials simulations experiments phenomena and applications
Ultrasonics, 2006Co-Authors: Jacqueline Vollmann, Dieter M Profunser, J Bryner, Jurg DualAbstract:A two-dimensional numerical simulation model for the elastodynamic wave propagation in two linear elastic, isotropic, joint half-spaces is presented. The border between the two half-spaced is graded in a way, that the values of the elastic properties and the densities vary smoothly (sinusoidally) from the values of one continuum to the values of the other continuum within a transition zone of a defined thickness. It is demonstrated, that a graded layer leads to a frequency and wavelength dependent refraction and reflection behavior of elastodynamic waves. Numerical results show that wavelengths which are long compared with the transition layer thickness are dominantly reflected whereas short waves are dominantly transmitted, a phenomena which does not occur in the case of an infinitely thin transition layer. Furthermore the frequency dependent reflection and transmission behavior of elastodynamic waves is verified experimentally. There the interface between two vapor deposited films is graded due to intermetallic diffusion effects. These graded microstructures are analyzed with a short-pulse-laser-acoustic set-up. The corresponding frequencies of the elastodynamic waves which are filtered with these functionally graded microstructures are in the range of 0.5 THz.
Marc Bonnet - One of the best experts on this subject based on the ideXlab platform.
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analysis of the error in constitutive equation approach for time harmonic elasticity imaging
Siam Journal on Applied Mathematics, 2019Co-Authors: Wilkins Aquino, Marc BonnetAbstract:We consider the identification of heterogeneous linear elastic moduli in the context of time-harmonic Elastodynamics. This inverse problem is formulated as the minimization of the modified error in...
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three dimensional transient elastodynamic inversion using an error in constitutive relation functional
Inverse Problems, 2015Co-Authors: Marc Bonnet, Wilkins AquinoAbstract:This work is concerned with large-scale three-dimensional (3D) inversion under transient elastodynamic conditions by means of the modified error in constitutive relation (MECR), an energy-based, cost functional. In contrast to quasi-static or frequency-domain contexts, time-domain formulations have so far seen very limited investigation. A peculiarity of time-domain MECR formulations is that each evaluation involves the solution of two elastodynamic problems (one forward, one backward), which moreover are coupled (unlike the case of L2 misfit functionals, where the forward state does not depend on the adjoint state). This coupling creates a major computational bottleneck, making MECR-based inversion difficult for spatially 2D or 3D configurations. To overcome this obstacle, we propose an approach whose main ingredients are (a) setting the entire computational procedure in a consistent time-discrete framework that incorporates the chosen time-stepping algorithm, and (b) using an iterative successive over-relaxation-like method for the resulting stationarity equations. The resulting MECR-based inversion algorithm is formulated under quite general conditions, allowing for 3D transient Elastodynamics, straightforward use of available parallel solvers, a wide array of time-stepping algorithms commonly used for transient structural dynamics, and flexible boundary condition and measurement settings. The proposed MECR algorithm is then demonstrated on computational experiments involving 2D and 3D transient Elastodynamics and up to over 500 000 unknown elastic moduli.
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three dimensional transient elastodynamic inversion using the modified error in constitutive relation
Journal of Physics: Conference Series, 2014Co-Authors: Marc Bonnet, Wilkins AquinoAbstract:This work is concerned with large-scale three-dimensional inversion under transient elastodynamic conditions by means of the modified error in constitutive relation (MECR), an energy-based cost functional. A peculiarity of time-domain MECR formulations is that each evaluation involves the computation of two elastodynamic states (one forward, one backward) which moreover are coupled. This coupling creates a major computational bottleneck, making MECR-based inversion difficult for spatially 2D or 3D configurations. To overcome this obstacle, we propose an approach whose main ingredients are (a) setting the entire computational procedure in a consistent time-discrete framework that incorporates the chosen time-stepping algorithm, and (b) using an iterative SOR-like method for the resulting stationarity equations. The resulting MECR-based inversion algorithm is demonstrated on a 3D transient elastodynamic example involving over 500,000 unknown elastic moduli.
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a multi level fast multipole bem for 3 d Elastodynamics in the frequency domain
Computer Methods in Applied Mechanics and Engineering, 2008Co-Authors: Marc Bonnet, Stephanie Chaillat, Jeanfrancois SemblatAbstract:To reduce computational complexity and memory requirement for 3-D Elastodynamics using the boundary element method (BEM), a multi-level fast multipole BEM (FM-BEM) is proposed. The diagonal form for the expansion of the elastodynamic fundamental solution is used, with a truncation parameter adjusted to the subdivision level, a feature necessary for achieving optimal computational efficiency. Both the single-level and mul ti-level forms of the elastodynamic FM-BEM are considered, with emphasis on the latter. Crucial implementation issues, including the truncation of the multipole expansion, the optimal number of levels, the direct and inverse extrapolation steps are examined in detail with the backing of numerical experiments. A complexity analysis for both the single-level and multi-level versions is conducted. The correctness and computational performances of the proposed elastodynamic FMM are demonstrated on numerical examples, featuring up to O(10 6 ) DOFs run on a single-processor PC and including the diffraction of an incident P plane wave by a semi-spherical or semi-ellipsoidal canyon, representative of topographic site effects.
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Topological derivative for the inverse scattering of elastic waves
Quaterly Journal Mechanics Applied Mathematics, 2004Co-Authors: B. B. Guzina, Marc BonnetAbstract:To establish an alternative analytical framework for the elastic-wave imaging of underground cavities, the focus of this study is an extension of the concept of topological derivative, rooted in elastostatics and shape optimization, to three-dimensional Elastodynamics involving semi-infinite and infinite solids. The main result of the proposed boundary integral approach is a formula for topological derivative, explicit in terms of the elastodynamic fundamental solution, obtained by an asymptotic expansion of the misfit-type cost functional with respect to the creation of an infinitesimal hole in an otherwise intact (semi-infinite or infinite) elastic medium. Valid for an arbitrary shape of the infinitesimal cavity, the formula involves the solution of six canonical exterior elastostatic problems, and becomes fully explicit when the vanishing cavity is spherical. A set of numerical results is included to illustrate the potential of topological derivative as a computationally efficient tool for exposing an approximate cavity topology, location, and shape via a grid-type exploration of the host solid. For a comprehensive solution to three-dimensional inverse scattering problems involving elastic waves, the proposed approach can be used most effectively as a pre-conditioning tool for more refined, albeit computationally intensive minimization-based imaging algorithms. To the authors' knowledge, an application of topological derivative to inverse scattering problems has not been attempted before; the methodology proposed in this paper could also be extended to acoustic problems.
Hossain Ahmed - One of the best experts on this subject based on the ideXlab platform.
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experimental verification and validation of nonlocal peridynamic approach for simulating guided lamb wave propagation and damage interaction
Structural Health Monitoring-an International Journal, 2019Co-Authors: Subir Patra, Hossain Ahmed, Mohammadsadegh Saadatzi, Sourav BanerjeeAbstract:In this article, experimental verification and validation of a peridynamics-based simulation technique, called peri-Elastodynamics, are presented while simulating the guided Lamb wave propagation a...
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Peri-Elastodynamic Simulations of Guided Ultrasonic Waves in Plate-Like Structure with Surface Mounted PZT
Sensors, 2018Co-Authors: Subir Patra, Hossain Ahmed, Sourav BanerjeeAbstract:Peridynamic based elastodynamic computation tool named Peri-Elastodynamics is proposed herein to simulate the three-dimensional (3D) Lamb wave modes in materials for the first time. Peri-Elastodynamics is a nonlocal meshless approach which is a scale-independent generalized technique to visualize the acoustic and ultrasonic waves in plate-like structure, micro-electro-mechanical systems (MEMS) and nanodevices for their respective characterization. In this article, the characteristics of the fundamental Lamb wave modes are simulated in a sample plate-like structure. Lamb wave modes are generated using a surface mounted piezoelectric (PZT) transducer which is actuated from the top surface. The proposed generalized Peri-Elastodynamics method is not only capable of simulating two dimensional (2D) in plane wave under plane strain condition formulated previously but also capable of accurately simulating the out of plane Symmetric and Antisymmetric Lamb wave modes in plate like structures in 3D. For structural health monitoring (SHM) of plate-like structures and nondestructive evaluation (NDE) of MEMS devices, it is necessary to simulate the 3D wave-damage interaction scenarios and visualize the different wave features due to damages. Hence, in addition, to simulating the guided ultrasonic wave modes in pristine material, Lamb waves were also simulated in a damaged plate. The accuracy of the proposed technique is verified by comparing the modes generated in the plate and the mode shapes across the thickness of the plate with theoretical wave analysis.