Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
4 results
Search Results
Item Acoustic behaviour of 3D printed bio-degradable micro-perforated panels with varying perforation cross-sections(Elsevier Ltd, 2021) Sailesh, R.; Yuvaraj, L.; Jeyaraj, J.; Doddamani, M.; Mailan Chinnapandi, L.B.Influence of perforations having arbitrarily varying cross-sections on the acoustic behaviour of 3D printed bio-degradable panels made of Poly Lactic Acid (PLA) is presented. Circular perforations having six different types of cross-sectional variations namely convergent-divergent (CD), divergent-convergent (DC), convergent (C), divergent (D) with two different perforation diameters are realized using Fused Filament Fabrication (FFF) based 3D printing. Sound absorption and transmission loss characteristics of these perforated panels are estimated through impedance tube technique. Results revealed that sound absorption of perforated panels with varying cross-section is better than uniform cross-sectional perforation for the given frequency range. Among, the different cross-sectional variations explored, comparable and lower transmission losses are exhibited by DC and D perforation pattern with respect to constant diameter 1 mm panel. The sound transmission results of all other five specimens were significantly higher than constant diameter 8 mm panel and observed to be increasing with frequency. Geometrical perforation variations are noted to be a very crucial factor in designing soundproof panels as presented in this work. The experimental results are compared with the numerical results and found to be in good agreement. Such numerical analysis paves the guidelines for designing optimum perforation geometries prior to the on-field testing of the functional prototypes. © 2020 Elsevier LtdItem Acoustic radiation and transmission loss of FG-Graphene composite plate under nonuniform edge loading(Elsevier Ltd, 2021) Gunasekaran, V.; Jeyaraj, J.; Mailan Chinnapandi, L.B.The influence of nonuniform edge loads on the acoustic response of a functionally graded graphene reinforced composite plate is investigated analytically. The energy method is implemented to calculate the buckling load (Pcr). An analytical method based on Reddy's third-order shear deformation theorem is used to obtain the vibration response, and acoustic response is obtained using Rayleigh Integral. The nature of edge load variation on buckling and vibro-acoustic response is significant. Free vibration mode shape changes with an increase in edge load and consequently affects the resonant amplitude of responses also especially for the plates with a higher aspect ratio. Volume fraction and dispersion pattern of graphene nano-platelets also influences the resonance amplitudes. Plate with FG?GRCC dispersion pattern has improved buckling and vibro-acoustic response behavior. Similarly, change in sound transmission loss level is significant in the stiffness region compared to the damping and mass dominated region. © 2021 Elsevier Masson SASItem Sound absorption and transmission loss of 3D printed wood fibre reinforced poly lactic acid with functionally graded perforations(Taylor and Francis Ltd., 2024) Sailesh, R.; Doddamani, M.; Mailan Chinnapandi, L.B.; Yuvaraj, L.; Pitchaimani, J.The effect of wood fibre reinforcement on acoustic properties of 3D printed poly lactic acid samples having varying cross-section perforation and functionally graded spherical perforations is presented. Acoustic characteristics like sound absorption as well as transmission loss are obtained using an impedance tube setup. Results revealed the benefits due to the addition of wood fibres in PLA improved samples’ sound transmission loss characteristics significantly. The sound absorption curve peaks shifted to low-frequency regions which are favourable to living beings. The material can be used in acoustic insulation for structural and transportation applications, especially where eco-friendliness and aesthetics are of major concern. © 2023 Informa UK Limited, trading as Taylor & Francis Group.Item Sound radiation and transmission behavior of auxetic core quadrilateral sandwich panels under supersonic flow(Taylor and Francis Ltd., 2025) Prajapati, V.K.; Jeyaraj, P.; Mailan Chinnapandi, L.B.Vibroacoustic performance of a quadrilateral sandwich plate under the synergetic effect of aerodynamic pressure and harmonic excitation is analyzed numerically. Layered approach is adopted to model the sandwich plate by considering the equivalent properties of the core and facings. Governing equations, developed utilizing Hamilton’s principle are solved based on differential quadrature approach to analyze the flutter frequency and forced vibration response. Subsequently, Rayleigh integral is used to estimate the acoustic response characteristics. Effect of geometric properties of the core (cell size, wall thickness, and inclined angle) and plate (leading, and trailing-edge angles) is examined. Critical aerodynamic pressure (CAP) is calculated first for the given case and the changes in response characteristics are investigated by varying the CAP. Results indicate that geometric parameters of the core does not influence the CAP, while the core thickness and the leading and trailing edge angles have significant effects. The sound power level (SWL) and transmission loss are observed to be maximum at CAP except in some cases of leading and trailing edge angles. © 2025 Taylor & Francis Group, LLC.