Porous materials are widely used for noise control. Often attached to a structure subjected to vibration, the porous layer contributes to diminish vibration by increasing structural damping and also reduce noise level in cavities by sound absorption. For optimal design, it is often necessary to know the viscoelastic properties of these materials in the frequency range relevant to their applicat...

This paper discusses a detailed study carried out on vibration characteristics of transversely loaded pultruted composite beams. A considerable discrepancy was noticed in the measured vibration of the transversely loaded beam and the calculated natural frequencies of the beam using Euler-Bernoulli beam theory. It has been observed that the natural frequencies of the beam were increased after la...

In this study, tapered polymer fiber sensors (TPFSs) have been employed to detect the vibration of a reinforced concrete beam (RC beam). The sensing principle was based on transmission modes theory. The natural frequency of an RC beam was theoretically analyzed. Experiments were carried out with sensors mounted on the surface or embedded in the RC beam. Vibration detection results agreed well w...

This paper studies free vibration of functionally graded beams Subjected to Axial Load that is simply supported at both ends lies on a continuous elastic foundation. The displacement field of beam is assumed based on Engesser-Timoshenko beam theory. The Young's modulus of beam is assumed to be graded continuously across the beam thickness. Applying the Hamilton's principle, the governing equati...

This paper investigates the feasibility of robust adaptive feedforward control for the vibration suppression of a smart flexible beam. The adaptive least mean square (LMS) feedforward control with sliding mode controller is developed. Finite element model of flexible beam is calculated. The developed adaptive control with sliding mode controller design is numerically verified on a flexible beam...

In this paper, the investigational results for a robust adaptive vibration control of a translating tensioned beam with a varying traveling speed are presented. The dynamics of the moving beam are modeled as an Euler-Bernoulli beam, in which the tension applied to the beam is given as a nonlinear spatiotemporally varying function. The moving beam span is divided into two parts, i.e., a controll...

The vibration of an elastic beam experiencing vortex-induced vibration is numerically analyzed through a wake-oscillator model using the finite differences method. The influence of the excited mode, the initial velocity, the shedding pulsation and the mass ratio on the energy transfer among modes and the vibration amplitude is determined. Multiple frequencies are detected, and the power spectra...

in this paper, surface and piezoelectric effects on the vibration behavior of nanowires (nws) are investigated by using a timoshenko beam model. the electric field equations and the governing equations of motion for the piezoelectric nws are derived with the consideration of surface effects. by the exact solution of the governing equations, an expression for the natural frequencies of nws with ...