The Experts below are selected from a list of 45492 Experts worldwide ranked by ideXlab platform
Mojtaba Mahzoon - One of the best experts on this subject based on the ideXlab platform.
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Investigating the stabilizing effect of stochastic excitation on a chaotic dynamical system
Nonlinear Dynamics, 2011Co-Authors: H. Emadi, Mojtaba MahzoonAbstract:The response of an interactive Mathieu–Duffing system in R 4, subjected to a harmonic excitation is investigated. For a deterministic Circular Frequency, chaotic behavior is observed. Subsequently it is shown that when the excitation becomes stochastic, chaos is subsided and trajectories tend to a diffused attracting set. The stabilizing effect of stochastic excitation is verified by finding the largest Lyapunov exponent for the two cases.
Garth M Reese - One of the best experts on this subject based on the ideXlab platform.
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fast Frequency sweep computations using a multi point pade based reconstruction method and an efficient iterative solver
International Journal for Numerical Methods in Engineering, 2007Co-Authors: Philip Avery, Charbel Farhat, Garth M ReeseAbstract:Problems of the form Z(σ) u(σ)=f(σ), where Z is a given matrix, f is a given vector, and σ is a Circular Frequency or Circular Frequency-related parameter arise in many applications including computational structural and fluid dynamics, and computational acoustics and electromagnetics. The straightforward solution of such problems for fine increments of σ is computationally prohibitive, particularly when Z is a large-scale matrix. This paper discusses an alternative solution approach based on the efficient computation of u and its successive derivatives with respect to σ at a few sample values of this parameter, and the reconstruction of the solution u(σ) in the Frequency band of interest using multi-point Pade approximants. This computational methodology is illustrated with applications from structural dynamics and underwater acoustic scattering. In each case, it is shown to reduce the CPU time required by the straightforward approach to Frequency sweep computations by two orders of magnitude. Copyright © 2006 John Wiley & Sons, Ltd.
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Fast Frequency sweep computations using a multi‐point Padé‐based reconstruction method and an efficient iterative solver
International Journal for Numerical Methods in Engineering, 2006Co-Authors: Philip Avery, Charbel Farhat, Garth M ReeseAbstract:Problems of the form Z(σ) u(σ)=f(σ), where Z is a given matrix, f is a given vector, and σ is a Circular Frequency or Circular Frequency-related parameter arise in many applications including computational structural and fluid dynamics, and computational acoustics and electromagnetics. The straightforward solution of such problems for fine increments of σ is computationally prohibitive, particularly when Z is a large-scale matrix. This paper discusses an alternative solution approach based on the efficient computation of u and its successive derivatives with respect to σ at a few sample values of this parameter, and the reconstruction of the solution u(σ) in the Frequency band of interest using multi-point Pade approximants. This computational methodology is illustrated with applications from structural dynamics and underwater acoustic scattering. In each case, it is shown to reduce the CPU time required by the straightforward approach to Frequency sweep computations by two orders of magnitude. Copyright © 2006 John Wiley & Sons, Ltd.
H. Emadi - One of the best experts on this subject based on the ideXlab platform.
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Investigating the stabilizing effect of stochastic excitation on a chaotic dynamical system
Nonlinear Dynamics, 2011Co-Authors: H. Emadi, Mojtaba MahzoonAbstract:The response of an interactive Mathieu–Duffing system in R 4, subjected to a harmonic excitation is investigated. For a deterministic Circular Frequency, chaotic behavior is observed. Subsequently it is shown that when the excitation becomes stochastic, chaos is subsided and trajectories tend to a diffused attracting set. The stabilizing effect of stochastic excitation is verified by finding the largest Lyapunov exponent for the two cases.
Sergey V. Kuznetsov - One of the best experts on this subject based on the ideXlab platform.
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Polarization of the longitudinal Pochhammer-Chree waves
Mechanics and Mechanical Engineering, 2020Co-Authors: Alla V. Ilyashenko, Sergey V. KuznetsovAbstract:AbstractThe exact solutions of the linear Pochhammer – Chree equation for propagating harmonic waves in a cylindrical rod, are analyzed. Spectral analysis of the matrix dispersion equation for longitudinal axially symmetric modes is performed. Analytical expressions for displacement fields are obtained. Variation of wave polarization on the free surface due to variation of Poisson’s ratio and Circular Frequency is analyzed. It is observed that at the phase speed coinciding with the bulk shear wave speed all the components of the displacement field vanish, meaning that no longitudinal axisymmetric Pochhammer – Chree wave can propagate at this phase speed.
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Pochhammer–Chree waves: polarization of the axially symmetric modes
Archive of Applied Mechanics, 2018Co-Authors: Alla V. Ilyashenko, Sergey V. KuznetsovAbstract:The exact solutions of the linear Pochhammer–Chree equation for propagating harmonic waves in a cylindrical rod are analyzed. Spectral analysis of the matrix dispersion equation for longitudinal axially symmetric modes is performed. Analytical expressions for displacement fields are obtained. Variation of wave polarization on the free surface due to variation of Poisson’s ratio and Circular Frequency is analyzed. It is observed that at the phase speed coinciding with the bulk shear speed (\(c_2\)) all the components of the displacement field vanish, meaning that no longitudinal axisymmetric Pochhammer–Chree wave can propagate at \(c_2\) phase speed.
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Abnormality of the longitudinal Pochhammer–Chree waves in the vicinity of C2 phase speed
Journal of Vibration and Control, 2018Co-Authors: Sergey V. KuznetsovAbstract:The exact solutions of the linear Pochhammer–Chree equation for propagating harmonic waves in a cylindrical rod are analyzed. Spectral analysis of the matrix dispersion equation for longitudinal axially symmetric modes is performed and analytical expressions for displacement fields are obtained. The variation of wave polarization on the free surface due to the variation of Poisson’s ratio and Circular Frequency is analyzed. It is observed that at the phase speed coinciding with the bulk shear speed all the components of the displacement field vanish, meaning that no longitudinal axisymmetric Pochhammer–Chree waves can propagate at this phase speed.
Philip Avery - One of the best experts on this subject based on the ideXlab platform.
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fast Frequency sweep computations using a multi point pade based reconstruction method and an efficient iterative solver
International Journal for Numerical Methods in Engineering, 2007Co-Authors: Philip Avery, Charbel Farhat, Garth M ReeseAbstract:Problems of the form Z(σ) u(σ)=f(σ), where Z is a given matrix, f is a given vector, and σ is a Circular Frequency or Circular Frequency-related parameter arise in many applications including computational structural and fluid dynamics, and computational acoustics and electromagnetics. The straightforward solution of such problems for fine increments of σ is computationally prohibitive, particularly when Z is a large-scale matrix. This paper discusses an alternative solution approach based on the efficient computation of u and its successive derivatives with respect to σ at a few sample values of this parameter, and the reconstruction of the solution u(σ) in the Frequency band of interest using multi-point Pade approximants. This computational methodology is illustrated with applications from structural dynamics and underwater acoustic scattering. In each case, it is shown to reduce the CPU time required by the straightforward approach to Frequency sweep computations by two orders of magnitude. Copyright © 2006 John Wiley & Sons, Ltd.
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Fast Frequency sweep computations using a multi‐point Padé‐based reconstruction method and an efficient iterative solver
International Journal for Numerical Methods in Engineering, 2006Co-Authors: Philip Avery, Charbel Farhat, Garth M ReeseAbstract:Problems of the form Z(σ) u(σ)=f(σ), where Z is a given matrix, f is a given vector, and σ is a Circular Frequency or Circular Frequency-related parameter arise in many applications including computational structural and fluid dynamics, and computational acoustics and electromagnetics. The straightforward solution of such problems for fine increments of σ is computationally prohibitive, particularly when Z is a large-scale matrix. This paper discusses an alternative solution approach based on the efficient computation of u and its successive derivatives with respect to σ at a few sample values of this parameter, and the reconstruction of the solution u(σ) in the Frequency band of interest using multi-point Pade approximants. This computational methodology is illustrated with applications from structural dynamics and underwater acoustic scattering. In each case, it is shown to reduce the CPU time required by the straightforward approach to Frequency sweep computations by two orders of magnitude. Copyright © 2006 John Wiley & Sons, Ltd.