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Yiu-Yin Lee

Bio: Yiu-Yin Lee is an academic researcher from City University of Hong Kong. The author has contributed to research in topics: Vibration & Nonlinear system. The author has an hindex of 21, co-authored 92 publications receiving 1727 citations. Previous affiliations of Yiu-Yin Lee include Hong Kong Polytechnic University & Old Dominion University.


Papers
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Journal ArticleDOI
TL;DR: The use of global optimization method can be an alternative to the finite difference/ finite element method in solving an engineering problem, and it is particularly attractive when an approximate solution is available or can be estimated easily.
Abstract: Many engineering problems are governed by partial differential equations which can be solved by analytical as well as numerical methods, and examples include the plasticity problem of a geotechnical system, seepage problem and elasticity problem. Although the governing differential equations can be solved by either iterative finite difference method or finite element, there are however limitations to these methods in some special cases which will be discussed in the present paper. The solutions of these governing differential equations can all be viewed as the stationary value of a functional. Using an approximate solution as the initial solution, the stationary value of the functional can be obtained easily by modern global optimization method. Through the comparisons between analytical solutions and fine mesh finite element analysis, the use of global optimization method will be demonstrated to be equivalent to the solutions of the governing partial differential equations. The use of global optimization method can be an alternative to the finite difference/ finite element method in solving an engineering problem, and it is particularly attractive when an approximate solution is available or can be estimated easily.

4 citations

Journal ArticleDOI
TL;DR: In this paper, an aircraft cabin panel embedded with piezoelectric sensors and actuators under sinusoidal or random excitation is studied experimentally, where the Independent Modal Space Control (IMSC) approach is employed in the controller design.
Abstract: In this paper, the active vibration suppression of an aircraft cabin panel embedded with piezoelectric sensors and actuators under sinusoidal or random excitation is studied experimentally. The Independent Modal Space Control (IMSC) approach is employed in the controller design. The piezoelectric sensors and actuators associated with the IMSC technique have been applied to the active vibration control of the aircraft panel, and shown to be effective in vibration control. A second order controller is selected in the control scheme to suppress the fundamental modal vibration response of the aircraft cabin panel. The mode shapes of the panel are experimentally obtained, and used as the parameters of the objective functions for minimizing the unwanted vibration responses by appropriately selecting the sensor and actuator gains. Based on the experimental results, it is found that the vibration levels of the open and closed loop systems differ by up to 5.0 dB (for sinusoidal excitation) and 7.4 dB (for random excitation), even when the control circuit is interfered by electrical and magnetic noises.

3 citations

Journal ArticleDOI
TL;DR: In this article, a multi-structural acoustic modal formulation is derived from two coupled partial differential equations representing the sound radiation from an enclosure panel subject to the acoustic pressure induced by a nonlinearly vibrating panel absorber.

3 citations

Journal ArticleDOI
09 Jul 2019-PLOS ONE
TL;DR: This study addresses the effects of large-amplitude vibration on the pressure-dependent absorption of a structure multiple-cavity system and the proposed harmonic balance method, which has recently been adopted to solve nonlinear beam problems and other nonlinear structural-acoustic problems.
Abstract: This study addresses the effects of large-amplitude vibration on the pressure-dependent absorption of a structure multiple-cavity system It is the first study to consider the effects of large-amplitude vibration and pressure-dependent absorption Previous studies considered only one of these two factors in the absorption calculation of a perforated panel absorber Nonlinear differential equations, which represent the structural vibration of a perforated panel absorber, are coupled with the wave equation, which represents the acoustic pressures induced within the cavities The coupled nonlinear differential equations are solved with the proposed harmonic balance method, which has recently been adopted to solve nonlinear beam problems and other nonlinear structural-acoustic problems Its main advantage is that when compared with the classical harmonic balance method, the proposed method generates fewer nonlinear algebraic equations during the solution process In addition, the solution form of the nonlinear differential equations from this classical method can be expressed in terms of a set of symbolic parameters with various physical meanings If a numerical method is used, there is no analytic solution form, and the final solution is a set of numerical values The effects of the excitation magnitude, cavity depth, perforation ratio, and hole diameter on the sound absorption of a panel absorber are investigated, and mode and solution convergence studies are also performed The solutions from the proposed harmonic balance method and a numerical integration method are compared The numerical results show that the present harmonic balance solutions agree reasonably well with those obtained with the numerical integration method Several important observations can be made First, perforation nonlinearity is a very important factor in the absorption of a panel absorber at the off structural resonant frequency range The settings of the hole diameter, perforation ratio, and cavity depth for optimal absorption differ greatly with consideration of perforation nonlinearity Second, the "jump up phenomenon," which does not occur in the case of linear perforation, is observed when perforation nonlinearity is considered Third, one or more absorption troughs, which worsen the average absorption performance, may exist in cases with multiple cavities

3 citations


Cited by
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Book ChapterDOI
01 Jan 1997
TL;DR: This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems and discusses the main points in the application to electromagnetic design, including formulation and implementation.
Abstract: This chapter introduces the finite element method (FEM) as a tool for solution of classical electromagnetic problems. Although we discuss the main points in the application of the finite element method to electromagnetic design, including formulation and implementation, those who seek deeper understanding of the finite element method should consult some of the works listed in the bibliography section.

1,820 citations

Journal ArticleDOI
B.B. Bauer1
01 Apr 1963

897 citations

Journal ArticleDOI
TL;DR: In this paper, a frequency-based damage detection (FBDD) method was proposed to locate damage from changes in natural frequencies and a damage-sizing algorithm to estimate crack-size from natural frequency perturbation.

605 citations

Journal ArticleDOI
TL;DR: In this paper, the free vibration problem for micro/nanobeams modelled after Eringen's nonlocal elasticity theory and Timoshenko beam theory is considered and the governing equations and the boundary conditions are derived using Hamilton's principle.
Abstract: This paper is concerned with the free vibration problem for micro/nanobeams modelled after Eringen's nonlocal elasticity theory and Timoshenko beam theory. The small scale effect is taken into consideration in the former theory while the effects of transverse shear deformation and rotary inertia are accounted for in the latter theory. The governing equations and the boundary conditions are derived using Hamilton's principle. These equations are solved analytically for the vibration frequencies of beams with various end conditions. The vibration solutions obtained provide a better representation of the vibration behaviour of short, stubby, micro/nanobeams where the effects of small scale, transverse shear deformation and rotary inertia are significant. The exact vibration solutions should serve as benchmark results for verifying numerically obtained solutions based on other beam models and solution techniques.

415 citations

Journal ArticleDOI
TL;DR: In this paper, an efficient and simple higher order shear and normal deformation theory is presented for functionally graded material (FGM) plates, which accounts for both shear deformation and thickness stretching effects by a hyperbolic variation of all displacements across the thickness.
Abstract: In this paper, an efficient and simple higher order shear and normal deformation theory is presented for functionally graded material (FGM) plates. By dividing the transverse displacement into bending, shear and thickness stretching parts, the number of unknowns and governing equations for the present theory is reduced, significantly facilitating engineering analysis. Indeed, the number of unknown functions involved in the present theory is only five, as opposed to six or even greater numbers in the case of other shear and normal deformation theories. The present theory accounts for both shear deformation and thickness stretching effects by a hyperbolic variation of all displacements across the thickness, and satisfies the stress-free boundary conditions on the upper and lower surfaces of the plate without requiring any shear correction factor. Equations of motion are derived from Hamilton’s principle. Analytical solutions for the bending and free vibration analysis are obtained for simply supported plates. The obtained results are compared with 3-dimensional and quasi-3-dimensional solutions and those predicted by other plate theories. It can be concluded that the present theory is not only accurate but also simple in predicting the bending and free vibration responses of functionally graded plates.

407 citations