Vibroacoustic response from thin exponential functionally graded plates

This paper presents an analytical investigation of the sound radiation behavior of a thin exponential functionally graded material plate using the classical plate theory and Rayleigh Integral with the elemental radiator approach. The material properties of the plate material, like Poisson’s ratio, are assumed constant, while Young’s Modulus and density are assumed to vary according to the exponential law distribution of the constituent materials in the transverse direction. The functionally graded material is modeled using a physical neutral surface instead of a geometric middle surface. The parametric effects of exponential law index, elastic modulus ratio, different constituent materials, damping loss factor on the sound radiation from exponential functionally graded plate (E-FGM) are illustrated. Sound power level in A-weighted dBA (loudness) scale has been illustrated to compare the sound power level (noise levels) radiated from power law (P-FGM), sigmoid law (S-FGM), and an exponential law (E-FGM) FGM plates. A-weighted dBA has also been illustrated for different modulus ratios and different material constituent E-FGM plates. The principal aim of this research paper is to predict the level of sound power level or noise level radiated by the vibrating E-FGM plates. The further objective is its applications in industries to envision how beneficial it will be to use the E-FGM plate compared to P-FGM and S-FGM plate. It has been found that, for the considered plate, the modulus ratio significantly influences sound power level and sound radiation efficiency. Effects of modulus ratios on the sound power level showed frequency shift over stiffness control region in the low-frequency range (first mode for all modulus ratios). The different values of damping loss factors do not significantly influence radiation efficiency for the given material constituents of the functionally graded plate. However, the selection of material constituents influences the radiation efficiency peak.