The Experts below are selected from a list of 388983 Experts worldwide ranked by ideXlab platform

Yufei Liu - One of the best experts on this subject based on the ideXlab platform.

Yu Chi Su - One of the best experts on this subject based on the ideXlab platform.

  • transient wave analysis of a cantilever timoshenko beam subjected to impact loading by laplace transform and normal Mode Methods
    International Journal of Solids and Structures, 2012
    Co-Authors: Yu Chi Su
    Abstract:

    Abstract This study applies two analytical approaches, Laplace transform and normal Mode Methods, to investigate the dynamic transient response of a cantilever Timoshenko beam subjected to impact forces. Explicit solutions for the normal Mode Method and the Laplace transform Method are presented. The Durbin Method is used to perform the Laplace inverse transformation, and numerical results based on these two approaches are compared. The comparison indicates that the normal Mode Method is more efficient than the Laplace transform Method in the transient response analysis of a cantilever Timoshenko beam, whereas the Laplace transform Method is more appropriate than the normal Mode Method when analyzing the complicated multi-span Timoshenko beam. Furthermore, a three-dimensional finite element cantilever beam Model is implemented. The results are compared with the transient responses for displacement, normal stress, shear stress, and the resonant frequencies of a Timoshenko beam and Bernoulli–Euler beam theories. The transient displacement response for a cantilever beam can be appropriately evaluated using the Timoshenko beam theory if the slender ratio is greater than 10 or using the Bernoulli–Euler beam theory if the slender ratio is greater than 100. Moreover, the resonant frequency of a cantilever beam can be accurately determined by the Timoshenko beam theory if the slender ratio is greater than 100 or by the Bernoulli–Euler beam theory if the slender ratio is greater than 400.

  • theoretical analysis of transient waves in a simply supported timoshenko beam by ray and normal Mode Methods
    International Journal of Solids and Structures, 2011
    Co-Authors: Yu Chi Su
    Abstract:

    Abstract The dynamic transient responses of a simply-supported Timoshenko beam subjected to an impact force are investigated by two theoretical approaches – ray and normal Mode Methods. The mathematical Methodology proposed in this study for the ray Method enable us to construct the solution for the interior source problem and to extend to solve the complicated problem for the multi span of the Timoshenko beam. Numerical results based on these two approaches are compared. The comparison in this study indicates that the normal Mode Method is more computationally efficient than the ray Method except for very short time after the impact. The long-time transient responses are easily calculated using the normal Mode Method. It is shown that the average long-time transient response converges to the corresponding static value. The Timoshenko beam theory is more accurate than the Bernoulli–Euler beam theory because it includes shear and rotary inertia. This study also provides the slender ratio for which the Bernoulli–Euler beam can be used for the transient-response analysis of the displacement. Moreover, the resonant frequencies obtained from finite element calculation based on the three-dimensional Model are compared with the results calculated using the Timoshenko beam and Bernoulli–Euler beam theories. It is noted in this study that the resonant frequency can be accurately determined by the Timoshenko beam theory if the slender ratio is larger than 100, and by the Bernoulli–Euler beam theory if the slender ratio is larger than 400.

Changyin Sun - One of the best experts on this subject based on the ideXlab platform.

  • neural network control of a two link flexible robotic manipulator using assumed Mode Method
    IEEE Transactions on Industrial Informatics, 2019
    Co-Authors: Hejia Gao, Chen Zhou, Changyin Sun
    Abstract:

    In this paper, the n-dimensional discretized Model of the two-link flexible manipulator is developed by the assumed Mode Method (AMM). Subsequently, based on the discretized dynamic Model, both full-state feedback control and output feedback control are investigated to achieve the trajectory tracking and vibration suppression. In order to guarantee the stability strictly, uniform ultimate boundedness (UUB) of the closed-loop system is realized by the Lyapunov's stability. Furthermore, through appropriately choosing control parameters, the states of the system will converge to zero within a small neighborhood. Eventually, extensive simulations and experiments on the Quanser platform for a two-link robotic manipulator are carried out to demonstrate the feasibility of the proposed neural network controller.

  • fuzzy neural network control of a flexible robotic manipulator using assumed Mode Method
    IEEE Transactions on Neural Networks, 2018
    Co-Authors: Changyin Sun, Hejia Gao
    Abstract:

    In this paper, in order to analyze the single-link flexible structure, the assumed Mode Method is employed to develop the dynamic Model. Based on the discrete dynamic Model, fuzzy neural network (NN) control is investigated to track the desired trajectory accurately and to suppress the flexible vibration maximally. To ensure the stability rigorously as the goal, the system is proved to be uniform ultimate boundedness by Lyapunov’s stability Method. Eventually, simulations verify that the proposed control strategy is effective, and the control performance is compared with the proportion derivative control. The experiments are implemented on the Quanser platform to further demonstrate the feasibility of the proposed fuzzy NN control.

Martijn C De Sterke - One of the best experts on this subject based on the ideXlab platform.

  • a flexible bloch Mode Method for computing complex band structures and impedances of two dimensional photonic crystals
    Journal of Applied Physics, 2012
    Co-Authors: Felix J Lawrence, Kokou B Dossou, L C Botten, R C Mcphedran, Martijn C De Sterke
    Abstract:

    We present a flexible Method that can calculate Bloch Modes, complex band structures, and impedances of two-dimensional photonic crystals from scattering data produced by widely available numerical tools. The Method generalizes previous work which relied on specialized multipole and finite element Method (FEM) techniques underpinning transfer matrix Methods. We describe the numerical technique for Mode extraction, and apply it to calculate a complex band structure and to design two photonic crystal antireflection coatings. We do this for frequencies at which other Methods fail, but which nevertheless are of significant practical interest.

  • a flexible bloch Mode Method for computing complex band structures and impedances of two dimensional photonic crystals
    arXiv: Optics, 2011
    Co-Authors: Felix J Lawrence, Kokou B Dossou, L C Botten, R C Mcphedran, Martijn C De Sterke
    Abstract:

    We present a flexible Method that can calculate Bloch Modes, complex band structures, and impedances of two-dimensional photonic crystals from scattering data produced by widely available numerical tools. The Method generalizes previous work which relied on specialized multipole and FEM techniques underpinning transfer matrix Methods. We describe the numerical technique for Mode extraction, and apply it to calculate a complex band structure and to design two photonic crystal antireflection coatings. We do this for frequencies at which other Methods fail, but which nevertheless are of significant practical interest.

Hejia Gao - One of the best experts on this subject based on the ideXlab platform.

  • neural network control of a two link flexible robotic manipulator using assumed Mode Method
    IEEE Transactions on Industrial Informatics, 2019
    Co-Authors: Hejia Gao, Chen Zhou, Changyin Sun
    Abstract:

    In this paper, the n-dimensional discretized Model of the two-link flexible manipulator is developed by the assumed Mode Method (AMM). Subsequently, based on the discretized dynamic Model, both full-state feedback control and output feedback control are investigated to achieve the trajectory tracking and vibration suppression. In order to guarantee the stability strictly, uniform ultimate boundedness (UUB) of the closed-loop system is realized by the Lyapunov's stability. Furthermore, through appropriately choosing control parameters, the states of the system will converge to zero within a small neighborhood. Eventually, extensive simulations and experiments on the Quanser platform for a two-link robotic manipulator are carried out to demonstrate the feasibility of the proposed neural network controller.

  • fuzzy neural network control of a flexible robotic manipulator using assumed Mode Method
    IEEE Transactions on Neural Networks, 2018
    Co-Authors: Changyin Sun, Hejia Gao
    Abstract:

    In this paper, in order to analyze the single-link flexible structure, the assumed Mode Method is employed to develop the dynamic Model. Based on the discrete dynamic Model, fuzzy neural network (NN) control is investigated to track the desired trajectory accurately and to suppress the flexible vibration maximally. To ensure the stability rigorously as the goal, the system is proved to be uniform ultimate boundedness by Lyapunov’s stability Method. Eventually, simulations verify that the proposed control strategy is effective, and the control performance is compared with the proportion derivative control. The experiments are implemented on the Quanser platform to further demonstrate the feasibility of the proposed fuzzy NN control.