Showing papers by "Yiu-Yin Lee published in 2006"
TL;DR: In this article, the effects of the antisymmetric mode vibration on the dynamic snap-through motion were studied, and it was shown that the autoparametric responses occur for large static buckled shapes when the resonance frequency of the symmetric mode is about twice that of antisymmetric mode.
37 citations
TL;DR: In this article, an exact analysis for free vibration of long-span continuous rectangular plates is presented based on the classical Kirchhoff plate theory, using the state space approach associated with joint coupling matrices.
28 citations
TL;DR: The model, named GRNNFA, is a fusion of the Fuzzy Adaptive Resonance Theory (FA) model and the General Regression Neural Network (GRNN) model, and it is shown to be statistically superior to other ANN models.
26 citations
TL;DR: In this paper, the authors investigated the large-amplitude multi-mode random response of thin shallow shells with rectangular planform at elevated temperatures using a finite element non-linear modal formulation.
Abstract: This paper investigates the large-amplitude multi-mode random response of thin shallow shells with rectangular planform at elevated temperatures using a finite element non-linear modal formulation. A thin laminated composite shallow shell element and the system equations of motion are developed. The system equations in structural node degrees-of-freedom (DOF) are transformed into modal co-ordinates, and the non-linear stiffness matrices are transformed into non-linear modal stiffness matrices. The number of modal equations is much smaller than the number of equations in structural node DOF. A numerical integration is employed to determine the random response. Thermal buckling deflections are obtained to explain the intermittent snap-through phenomenon. The natural frequencies of the infinitesimal vibration about the thermally buckled equilibrium positions (BEPs) are studied, and it is found that there is great difference between the frequencies about the primary (positive) and the secondary (negative) BEPs. All three types of motion: (i) linear random vibration about the primary BEP, (ii) intermittent snap-through between the two BEPs, and (iii) non-linear large-amplitude random vibration over the two BEPs, can be predicted. Copyright © 2006 John Wiley & Sons, Ltd.
24 citations
TL;DR: In this paper, a probabilistic approach is introduced and used to find the optimal values assigned to the uncertain parameters of a room acoustic model, which is used for the reconstruction of the interior sound pressure distribution.
7 citations
TL;DR: In this paper, a theoretical analysis for the large amplitude vibration of symmetric and unsymmetric composite plates using the non-linear finite element modal reduction method is presented, and the frequency ratios for the fundamental mode and the higher modes of a composite plate at various values of maximum deflection are determined by using the Runge-Kutta numerical integration scheme.
Abstract: A theoretical analysis is presented for the large amplitude vibration of symmetric and unsymmetric composite plates using the non-linear finite element modal reduction method. The problem is first reduced to a set of Duffing-type modal equations using the finite element modal reduction method. The main advantage of the proposed approach is that no updating of the non-linear stiffness matrices is needed. Without loss of generality, accurate frequency ratios for the fundamental mode and the higher modes of a composite plate at various values of maximum deflection are then determined by using the Runge–Kutta numerical integration scheme. The procedure for obtaining proper initial conditions for the periodic plate motions is very time consuming. Thus, an alternative scheme (the harmonic balance method) is adopted and assessed, as it was employed to formulate the large amplitude free vibration of beams in a previous study, and the results agreed well with the elliptic solution. The numerical results that are obtained with the harmonic balance method agree reasonably well with those obtained with the Runge–Kutta method. The contribution of each linear mode to the maximum deflection of a plate can also be obtained. The frequency ratios for isotropic and composite plates at various maximum deflections are presented, and convergence of frequencies with the number of finite elements, number of linear modes, and number of harmonic terms is also studied. Copyright © 2005 John Wiley & Sons, Ltd.
4 citations
15 Jun 2006-Jsme International Journal Series C-mechanical Systems Machine Elements and Manufacturing
TL;DR: In this paper, a plastic hammer is used to excite the cement viaduct model at the centre and at the supporting edge position of the cross-section separately, and the results of analysis using a finite element method are confirmed by the experimental findings of crosssectional modes.
Abstract: This paper identifies the method to control the vibration responses of a concrete viaduct model under impulsive force excitation. The frequencies and mode shapes of resonances of the bending vibration across the section can control the magnitude of the structure-borne noise radiation. A plastic hammer is used to excite the cement viaduct model at the centre and at the supporting edge position of the cross-section separately. The results of analysis using a Finite Element Method are confirmed by the experimental findings of the cross-sectional modes. The findings showed that the local modes are of two types: (1) Centre mode ─ the centre of top panel can move but the edge is fixed. (2) Edge (web) mode ─ the centre of panel is fixed but the edge (supported by web) can move. It is found that by supporting the machines on the edge, the center mode will not be excited but the combined mode of edge and center mode can give rise to significant noise radiation. A honeycomb panel with high resonance frequency is used to reduce the vibration transmission from this combined mode. The design can be used as an alternative to floating slab for reducing noise.
4 citations