Faculty Publications
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Item Sound radiation and transmission loss characteristics of a honeycomb sandwich panel with composite facings: Effect of inherent material damping(Academic Press, 2016) Arunkumar, M.P.; Jagadeesh, M.; Jeyaraj, J.; Gangadharan, K.V.; Mailan Chinnapandi, M.C.L.This paper presents the results of numerical studies carried out on vibro-acoustic and sound transmission loss behaviour of aluminium honeycomb core sandwich panel with fibre reinforced plastic (FRP) facings. Layered structural shell element with equivalent orthotropic elastic properties of core and orthotropic properties of FRP facing layer is used to predict the free and forced vibration characteristics. Followed by this, acoustic response and transmission loss characteristics are obtained using Rayleigh integral. Vibration and acoustic characteristics of FRP sandwich panels are compared with aluminium sandwich panels. The result reveals that FRP panel has better vibro-acoustic and transmission loss characteristics due to high stiffness and inherent material damping associated with them. Resonant amplitudes of the response are fully controlled by modal damping factors calculated based on modal strain energy. It is also demonstrated that FRP panel can be used to replace the aluminium panel without losing acoustic comfort with nearly 40 percent weight reduction. © 2016 Elsevier LtdItem Influence of nature of core on vibro acoustic behavior of sandwich aerospace structures(Elsevier Masson SAS 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2016) Arunkumar, M.P.; Jeyaraj, P.; Gangadharan, K.V.; Mailan Chinnapandi, M.C.This paper presents the study of influence of core geometry on vibration and acoustic response characteristics of sandwich panels which are used as aerospace structures. Sandwich panels considered in this research work are: (a) Honeycomb core, (b) Truss and Z core, (c) Foam core. The present study has found that (i) For a honeycomb core sandwich panel in due consideration to space constraint, the better acoustic comfort can be achieved by reducing the core height and increasing the face sheet thickness. (ii) It is demonstrated that, for a honeycomb core sandwich panel, vibration and acoustic response is not sensitive to the cell size. (iii) It is observed that, triangular core gives better acoustic comfort for the truss core sandwich panel compared to other type of core. (iv) For foam core sandwich panels, it is observed that sandwich panel with carbon-epoxy (high stiffness) face sheet radiates less sound in the lower frequency range (0–100 Hz). While the sandwich panel with Titanium (high density) face sheet radiates less sound at the higher frequencies. In order to reduce the preprocessing time and computational effort throughout the analysis in the present study, equivalent 2D elastic properties are calculated and used to find out the vibration and acoustic response characteristics. © 2016 Elsevier Masson SASItem Vibro-acoustic response and sound transmission loss characteristics of truss core sandwich panel filled with foam(Elsevier Masson SAS 62 rue Camille Desmoulins Issy les Moulineaux Cedex 92442, 2018) Arunkumar, M.P.; Jeyaraj, P.; Gangadharan, K.V.; Mailan Chinnapandi, M.C.This paper presents the studies carried out for improving the acoustic behavior of truss core sandwich panel, which is mostly used in aerospace structural applications. The empty space of the truss core is filled with polyurethane foam (PUF) to achieve better vibro-acoustic and sound transmission loss characteristics. Initially equivalent elastic properties of the foam filled truss core sandwich panel are calculated. Then, the vibration response of the panel under a harmonic excitation is obtained based on the equivalent 2D finite element model. Finally, the vibration response is given as an input to the Rayleigh integral code built in-house to obtain the acoustic and sound transmission loss characteristics. The results revealed that PUF filling of the empty space of the truss core, significantly reduces resonant amplitudes of both vibration and acoustic responses. It is also observed that foam filling reduces the overall sound power level significantly. Similarly, sound transmission loss studies revealed that, sudden dips at resonance frequencies are significantly reduced. Also an experiment is conducted on forced vibration response of honeycomb core sandwich panel to show that equivalent 2D model can be used for predicting sound power level and transmission loss behavior. © 2018 Elsevier Masson SASItem An exact solution for vibro-acoustic response of smart sandwich panels with MEE composite Layer(Elsevier Ltd, 2022) Arunkumar, M.P.; Bhagat, V.S.; Geng, Q.; Li, Y.; Jeyaraj, J.To the best of our knowledge, this is the first endeavor to provide an exact solution for a vibro-acoustic response of Magneto-electro-elastic (MEE) composite plate and sandwich panels with MEE facings. The governing equation of motion is developed using Hamilton's principle considering the third-order shear deformation theory to account for transverse shear. Based on boundary conditions and the Maxwell equation, the variation of electric and magnetic potentials are adopted along the thickness of the MEE composite layer. Analysis of the vibro-acoustic response of sandwich panels which are extensively used in aerospace structures such as cellular, trapezoidal, triangular, and honeycomb are presented. Influences of electric and magnetic potential on the vibro-acoustic response are also presented for the different types of truss core and honeycomb core sandwich panels. © 2022Item An exact solution for vibro-acoustic response of MEE composite plate(Elsevier Ltd, 2022) Arunkumar, M.P.; Bhagat, V.S.; Swetha, S.; Geng, Q.; Jeyaraj, J.; Li, Y.To the best of our knowledge, this is the first endeavor to present an exact solution to predict vibro-acoustic characteristics of Magneto-electro-elastic (MEE) composite plate. The transverse and in-plane fields are considered based on thin-plate conditions. The variation of electric and magnetic potentials is determined according to electromagnetic boundary conditions and the Maxwell equation. The stress resultants and mass inertias are used in Hamilton's principle to generate the governing equation. Here the mathematical formulation is developed using third-order shear deformation theory. Also in this work, the dynamic displacement responses are provided by finding five undetermined mode coefficients relevant to u, v, w, ϕx, and ϕy to predict forced vibration response. The forced vibration response obtained based on the developed governing equation is used to calculate the acoustic characteristics using the Rayleigh integral. The effect of magnetic and electric potential is shown in the acoustic responses. From the results, it is understood that the acoustic responses are highly influenced by the applied magnetic and electric potential. The radiation efficiency of the MEE plate did not show any variations in the lower frequency and it shows the variation near the resonant frequencies on the application of electric and magnetic potential. © 2022 Elsevier Ltd