Browsing by Author "Pitchaimani, J."

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3D Printed Thick Micro-Perforated Panel with Graded Perforation for Practical Wall Sound Absorption Applications
(Springer, 2024) Shafeer, M.; Pitchaimani, J.; Doddamani, M.
In recent years, noise pollution has been recognized as a significant environmental issue, and using sustainable materials as sound-absorbing building materials have drawn considerable attention. The influence of graded perforations on the acoustic characteristics of a 3D printed bio-degradable thick micro-perforated panel (MPP) having graded perforation and made of Poly Lactic Acid is presented. Thicker panels are considered owing to the mechanical strength required for practical wall applications. A fused deposition modeling based 3D printer is used to fabricate the MPPs with graded cylindrical perforations and different patterning of perforations. The sound absorption coefficient is measured using the impedance tube technique and compared with theoretical results obtained using an equivalent electro-acoustic model. Results revealed that for normal incidence, the absorption coefficient is only dependent on the overall perforation ratio of the panel, irrespective of the perforation gradation and patterning of perforation. This gives the freedom to distribute the perforation aesthetically for interior wall application. This work also proposes the effective perforation ratio approach to predict the sound absorption coefficient (SAC) of MPPs with graded perforation. For multi-thickness MPPs and MPPs with linearly graded thickness, improved sound absorption characteristics were observed both in terms of bandwidth of absorption and peak value of SAC compared to the conventional constant thickness MPPs. © Australian Acoustical Society 2023.
A short banana fiber—PLA filament for 3D printing: Development and characterization
(John Wiley and Sons Inc, 2025) Mohamed Shafeer, P.P.; Pitchaimani, J.; Doddamani, M.
This study aims to develop a 3D printable composite filament using short banana fiber and polylactic acid (PLA). The filament was acquired through a single screw extruder, employing various blending techniques. Various fiber loadings were examined, impacting PLA's mechanical, thermal, and printability properties. The results revealed altered mechanical characteristics, with reduced tensile and flexural properties compared with pure PLA. However, these values are at an acceptable level for non-structural applications. Compared with previous works, the filament developed in the present work is found out to be second strongest among the cellulose fiber-reinforced PLA filaments. 3D printing with the composite filament encountered no significant issues. A modified mixing method improved mechanical characteristics, although 3D-printed samples showed deteriorated mechanical characteristics due to poor interfacial bonding. This research introduces an environmentally viable strategy for advancing 3D printing technology by integrating banana fibers into PLA filament. The proposed strategy can be effectively utilized in making cellulose/PLA filaments for 3D printing applications. This innovative approach preserves PLA's natural biodegradability while carefully managing the integration of banana fibers and their potential effects on mechanical properties. Highlights: Fiber loading influences mechanical, with minimal impact on thermal properties. Solution casting improved fiber/matrix bonding and filler homogeneity. Plasticizing effect reduces the tensile strength. Modified mixing resulted in even filament diameter and improved tensile properties. © 2024 Society of Plastics Engineers.
Acoustic characterization of natural areca catechu fiber-reinforced flexible polyurethane foam composites
(John Wiley and Sons Inc, 2024) Mb, S.; Kumar, G.C.M.; Pitchaimani, J.
The development of acoustic absorbers from natural resources is a novel approach in acoustics. In the current study, the effect of unprocessed raw areca fiber (AF) particle reinforcement on the sound absorption (SA) behavior of polyurethane (PU) foam composites is investigated. Influences of fiber weight percentage and graded distribution of fiber with varying fiber weight percentage on the SA coefficient (SAC) of the composite foams are examined through the impedance tube approach. Morphological studies are carried out with the help of FESEM images to investigate the acoustic energy dissipation mechanism of PU foam and its composites. It is found that the SA capability of the composite foam is enhanced by increased fiber weight percentage, graded distribution of fiber wt%, varying sample thickness, and air cavity length. In general, PU-AF composite specimens show a peak SA value of 0.95 around 450 Hz, which is not the case for other natural fiber results available in the literature. Theoretical results predicted using the JCA (Johnson-Champoux Allard) model agree with the experimental results. © 2023 Wiley Periodicals LLC.
Acoustic response of bi-directional functionally graded beam under axially varying load
(SAGE Publications Inc., 2023) Somi Naidu, S.N.; Pitchaimani, J.; Mailan Chinnapandi, L.B.
This paper investigates the effects of bi-directional gradation, length-to-height ratio, and end conditions on the acoustic behaviour of bi-directionally varying functional graded beams. The acoustic responses, including sound-power level (dB), sound-pressure level (dB), and sound-radiation efficiency, are evaluated using Rayleigh’s integral and modal superposition method. The sound power levels are presented up to the selected bandwidth, as well as the octave band center frequency. In contrast, the sound pressure levels are presented as contour plots and in directivity pattern. The buckling load, calculated for quadratically decreasing axial load, is applied in increments from 0 to its highest value. The study reveals that the highest value in the gradation indexes in both directions significantly influences the sound power levels. It is also evident from the study that thin beams have higher sound power levels compared to thick beams. The directivity pattern reveals that bi-directional functionally graded beams predict higher sound pressure levels at the critical buckling load. From the current acoustic study, it is observed that both structural and end stiffness are influential factors in sound power levels (dB) and sound pressure levels (dB). © The Author(s) 2023.
Applicability Two-Dimensional Differential Integral Quadrature Method in Vibration Analysis of Multi-Directional Functionally Graded Porous Viscoelastic Plates
(John Wiley and Sons Ltd, 2025) Mohamed, S.A.; Mohamed, N.; Assie, A.E.; Eltaher, M.A.; Pitchaimani, J.; Abo-Bakr, R.
This study formulates a differential integral quadrature method (DIQM) to analyze the free vibration characteristics of multi-directional functionally graded material (MFGM) viscoelastic porous plates. The kinematic relations are derived using a unified shear deformation plate theory, while material behavior is governed by the integer-order Kelvin-Voigt viscoelastic constitutive model. Power-law functions define the spatial gradation of material constituents along the length, width, and thickness directions. Two distinct porosity distributions are incorporated to characterize void and cavity variations through the plate's thickness. Hamilton's variational principle yields five coupled governing equations expressed as partial differential equations with variable coefficients. The differential quadrature method (DQM) discretizes these governing equations, with integral quadrature method (IQM) efficiently resolving the variable coefficients. This discretization results in an algebraic system constituting a quadratic eigenvalue problem. The eigenvalues' real and imaginary components provide the damping coefficients and natural frequencies, respectively. The proposed model and solution methodology are validated against established unified shear formulations, MFGM porous plates, and viscoelastic plate solutions available in literature. Comprehensive parametric studies systematically investigate the influence of material gradation indices, porosity parameters, boundary conditions, and viscoelastic coefficients on the natural vibration response of thick MFGM viscoelastic porous plates. The results demonstrate that an increase in either of the material gradation indices leads to a decrease in both of the real and imaginary parts of the fundamental frequencies. © 2025 John Wiley & Sons Ltd.
Comparative assessment of a novel 8/18 multi-teeth with conventional 8/10 in-wheel SRM for an E-Scooter
(Taylor and Francis Ltd., 2024) Bhaktha, S.; Ramnihor, G.R.; Sahu, M.; Jogi, A.; Pitchaimani, J.; Gangadharan, K.V.
Electric scooters are increasingly gaining popularity in India owing to rising global crude oil prices and rising levels of vehicular pollution. Most of them are currently powered by expensive in-wheel (IW) permanent magnet (PM) brushless DC motors. Owing to their simplicity, and ruggedness while being cost-effective (since they do not employ PMs), switched reluctance motors (SRMs) are a viable alternative. Despite these benefits, SRMs possess drawbacks such as low torque density and inferior efficiency. Recently, a multi-teeth (MT) SRM with an improved performance was reported. However, the design of MTSRM topologies and their electromagnetic performance have not been explored sufficiently. In this paper, a design formula governing the selection of the number of MT and rotor poles for MTSRMs has been proposed. Using this, a novel four-phase 8/18 IW-MTSRM is derived and proposed for an E-scooter. The characteristics of the proposed SRM are numerically compared with a conventional 8/10 SRM based on magnetic characteristics, efficiencies and steady-state operation for the complete torque-speed range. Results indicate that the proposed 8/18 MTSRM has a higher peak torque capacity, torque density, superior drive cycle efficiency and reduced torque ripple. Further, the FEA model is validated experimentally on a downsized 8/18 MTSRM prototype. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Driving Cycle-Based Design Optimization and Experimental Verification of a Switched Reluctance Motor for an E-Rickshaw
(Institute of Electrical and Electronics Engineers Inc., 2024) Bhaktha, B.S.; Jose, N.; Vamshik, M.; Pitchaimani, J.; Gangadharan, K.V.
This article deals with the design and optimization of a 2 kW switched reluctance motor (SRM) for an electric rickshaw (E-rickshaw). Previously published research on SRM optimization has mostly focused on the optimization of their design and control variables only at the rated conditions. In electric vehicle (EV) applications, the load operating points (LOPs) of a traction motor are dynamic and spread widely across the torque speed envelope. To enhance their overall performance, it is vital to include them in the design optimization process; therefore, in this article, a novel procedure for implementing the multiobjective design optimization (MODO) of an SRM based on a driving cycle has been demonstrated. Higher starting torque and torque density with reduced electromagnetic losses throughout the driving cycle are established as the design objectives, subject to practical restrictions on current density and slot fill factor. The design objectives have been accurately evaluated through transient finite element analysis (FEA) and a computationally efficient SRM drive model (developed in MATLAB/Simulink) with consideration of the excitation control parameters. Kriging models have been constructed to reduce the computation cost of FEA during the optimization process. Then, a nondominated sorting genetic algorithm II (NSGA II) based multiobjective optimization coupled with the constructed Kriging models is conducted to generate a Pareto front. An optimal design that offers the best balance between the design objectives is selected from the Pareto-optimal set, and the dimensions of corresponding design variables are used to build a prototype. Finally, the static and dynamic performance of the SRM prototype are experimentally evaluated and validated with the FEA simulations. © 2024 IEEE.
Driving cycle-centric design optimization and experimental validation of high torque density outer rotor 8/18 MTSRM for an E-Bike
(Elsevier Ltd, 2025) B, S.B.; Sarma, S.; Vamshik, M.; Pitchaimani, J.; Bhaktha, K.V.
This paper presents an innovative methodology for optimizing the design parameters of a 500 W low-speed outer rotor switched reluctance motor (OR-SRM) for an electric bicycle (E-bike) in accordance with a driving cycle. Design optimization of SRMs based on driving cycles has been minimally explored in the literature, with all existing research focusing exclusively on high-speed electric vehicle (EV) applications. These studies utilized computationally intensive dynamic current analysis methods to account for the significant dynamic effects incurred. Given the E-bike's low-speed characteristics, the present study mitigates the computational load of design optimization through static current analysis. A high torque density 8/18 OR-multi-teeth (MT) SRM topology has been proposed. The benefits of this topology, such as mass, cost, torque ripple reductions, and improved torque density, have been highlighted through a comparison with a conventional 6/10 OR-SRM topology. The reliability of the finite element analysis models used in this study is validated through experiments conducted on an 8/18 OR-MTSRM prototype. The multi-objective design optimization aims to maximize starting torque and minimize torque ripple and electromagnetic losses throughout the driving cycle. The efficacy of the optimization is confirmed by the enhancement in the performance parameters of the optimal design compared to the preliminary design. © 2025 Elsevier Ltd
Experimental investigation of embedded neck designs and core geometries for enhanced low-frequency sound absorption in 3D printed micro-perforated panels
(Elsevier Ltd, 2025) Mohamed Shafeer, P.P.; Pitchaimani, J.; Doddamani, M.
This study presents an experimental investigation into the acoustic performance enhancement of micro-perforated panel (MPP) based liners through structural modifications involving embedded necks and engineered core geometries. All samples were produced through fused deposition modeling with polylactic acid as the filament material. Sound absorption coefficients were measured using an impedance tube method (ASTM E1050) in a 50–1600 Hz frequency range. Initially, cylindrical necks of varying lengths were analyzed to assess the impact of neck extension on sound absorption, particularly in the low-frequency range. This was followed by evaluating non-cylindrical embedded neck profiles (converging, diverging, converging-diverging, and diverging-converging) for a fixed neck length. Then the effect of engineered core topologies, including square, hexagonal, re-entrant, and hybrid geometries, is studied on broadband absorption. Finally, selected core designs were combined with embedded necks to examine the synergetic effects. Incorporation of a cylindrical embedded neck results in shifting of peak absorption to lower frequency (328 Hz for 5 mm), with a weight reduction of 37.5 % compared to the typical MPP. The peak value and the frequency are not sensitive to different types of non-cylindrical embedded necks, and there is about 20 % improvement in the bandwidth with a trade-off of approximately 100 Hz shift in peak frequency towards the higher frequency side. Structured cores enhanced peak frequency (up to 25 %) and bandwidth (up to 10 %). Combined configurations exhibited limited synergistic enhancement, likely due to resonator interference effects. This study introduces a novel geometric strategy for tuning acoustic performance via coordinated neck and core design variations, enabling compact, lightweight, and tunable acoustic liners for low-frequency absorption. © 2025 Elsevier Ltd
Exploring the acoustic potential of 3D printed micro-perforated panels: A comparative analysis
(Elsevier Ltd, 2024) Deepak; Pitchaimani, J.; Raghukiran, R.; Mailan Chinnapandi, L.B.
In the present study, the sound absorption performance of inhomogeneous Micro-Perforated Panels (MPPs) with multiple cavities is investigated. Two models, a three-cavity system and a four-cavity system, are proposed and a numerical study is performed using MATLAB. The models are validated through experimental analysis in an impedance tube. The study meticulously varies the geometrical parameters, including pore diameter, thickness of the MPP, perforation ratio, and back-cavity length. It is found that MPPs with a greater number of sub-cavities have a better sound absorption coefficient than two-cavity systems. The results suggest that the back air cavity is predominantly responsible for multiple peaks, ensuring wideband sound absorption. It is also found that smaller perforation ratios for sub-cavities with larger pore diameters improve sound absorption performance in the lower frequency region. The study indicates that a pore diameter of less than 0.5 mm should be used for better sound absorption above the range of 800–850 Hz, and back cavity length has greater control than pore diameter between 850 Hz and 2000 Hz to make the curve smooth with less fluctuation. The findings have significant implications for the design of MPPs for real-world applications. © 2024 The Authors
Flutter behavior of quadrilateral auxetic core sandwich plate with bio-inspired three-phase composite facings numerical analysis and experimental verification
(SAGE Publications Ltd, 2025) Prajapati, V.K.; Pitchaimani, J.
Flutter characteristics of auxetic core quadrilateral sandwich plates with three-phase bio-inspired laminated composite facings are presented. The core is made of aluminum, while the facings are made of graphene nanoplatelets dispersed in bio-inspired glass fiber/epoxy laminates. The equations of motion are obtained using Reissner-Mindlin plate theory and Hamilton’s approach and then solved with the help of differential quadrature method. Experimental verification of free vibration is done for isotropic and hexagonal honeycomb core sandwich panels. Influences of core parameters (aspect ratio, inclined angle, and thickness-to-width ratio), mass fraction of graphene nanoplatelets and fibers, various graphene nanoplatelet distribution patterns, the geometry and aspect ratio of the plate, and bio-inspired layup scheme of laminated facings on the flutter characteristic are explored. The critical aerodynamic pressure is not sensitive to the core parameters and the dispersion pattern of graphene nanoplatelets. Critical aerodynamic pressure of the panel increases significantly with increase in the mass fractions of fiber and graphene nanoplatelet. Furthermore, the increase in the plate angles results in reduced critical aerodynamic pressure. Facing laminate made of helicoidal type bio-inspired lay-up scheme with lower rotation angle enhances the critical aerodynamic pressure compared to the conventional uni-directional, cross-ply, and quasi-isotropic lay-ups. © IMechE 2024.
Free vibration and buckling response of functionally graded triply periodic minimal surface beams considering neutral axis dislocation
(SAGE Publications Inc., 2023) Kurup, M.; Pitchaimani, J.
The work pioneers a novel investigation into the free vibration and buckling behavior of triply periodic minimal surface beams, characterized by diverse distribution profiles. Using Euler-Bernoulli theory, under various boundary conditions, the investigation is carried out on four TPMS (Triply Periodic Minimal Surface) patterns, mainly gyroid, primitive, diamond and IWP (I-graph-wrapped package). The neutral axis would not coincide with the geometric center of the functionally graded beams so the neutral shift effect is taken into consideration appropriately. Governing differential equations are derived and the solutions are obtained numerically using the Ritz method. The mode shapes have also been calculated. It can be concluded that the type of pattern and distribution profile, boundary conditions, grade and neutral axis shift effect play a vital role in the prediction of vibration and buckling properties. © The Author(s) 2023.
Influence of Stator Structure on the Electromagnetic Performance of an In-Wheel Multi-teeth SRM
(Springer, 2025) Bhaktha, S.; Ramnihor, G.R.; Pitchaimani, J.; Gangadharan, K.V.
Compared to traditional switched reluctance motor (SRM) topologies, the multi-teeth (MT) SRM topology has been reported to be beneficial for in-wheel motor applications because of its superior torque density, efficiency, with minimized torque ripple. In this paper, a four-phase 8/18 IW-MTSRM with two different stator structures, namely the trapezoidal-shaped stator structure (TSSS) and the Y-shaped stator structure (YSSS) are designed and analyzed. Using two-dimensional (2D) electromagnetic static finite element analysis, the performance metrics including average torque, peak torque capacity, and torque ripple are compared under the condition of constant copper loss. Based on the results obtained, this study attempts to offer guidance and suggestions for choosing an appropriate stator structure among IW-MTSRMs according to the application requirement. To validate the FEA model employed in this study, an 8/18 IW-MTSRM with the TSSS is prototyped and tested experimentally. The experimental results are observed to agree with the FEA model. © The Institution of Engineers (India) 2024.
Localised edge load dependent aeroelastic stability of porous plates with GPL reinforcement under the influence of supersonic flow
(Elsevier Ltd, 2025) Twinkle, T.; Pitchaimani, J.; Lacarbonara, W.
Buckling and flutter characteristics of porous plates with graphene platelet (GPL) reinforcement subjected to concentrated edge loads are explored for the first time. The plate is considered to be having simultaneous variation of GPL and porosity content through the thickness. For the porous plate with GPL reinforcement, the effective material properties are determined using the Halpin–Tsai micromechanical model. Further, to obtain the solutions the Galerkin method is employed for the governing differential equations derived using Hamilton's principle. The results of the present model are validated for accuracy and reliability by comparing them with the results available in the open literature for buckling, free vibration, and flutter studies. To study the flutter behaviour of plates under the effect of different types of concentrated edge loads, several parametric studies are performed for the first time. Additionally, the influence of GPL weight percentage, amount of porosity, dispersion of porosity, and GPL on the flutter instability is investigated. The results indicate that the type of concentrated edge load has a major impact on the flutter instability of the plate with centrally distributed (case 1) type of loading leading to a higher reduction in flutter pressure. Further, an increase in porosity and GPL content significantly affects the flutter and buckling coefficient values. © 2024 Elsevier Ltd
Mode-I fracture behaviour of aramid/glass-epoxy interply hybrid composites
(SAGE Publications Ltd, 2025) Kanakannavar, S.; Biradar, S.; Hiremath, S.; Rajole, S.; Pitchaimani, J.; Kulkarni, S.M.; Goh, K.-L.
This article presents the influence of hybridisation of aramid and glass fibre woven fabric on fracture toughness (KIC) of the composites. Experiments using single-edge-notched-bending (SENB) were conducted to investigate the hybridisation effect on the Mode I fracture toughness specimen of aramid/glass laminates. The results revealed that the aramid epoxy composites yielded the highest KIC, followed by aramid/glass epoxy hybrid composites, and finally, glass epoxy composites, which exhibited the lowest KIC. Fracture micrographs of the hybrid composites showed similar fracture patterns – fibre pullout, fibre rupture and matrix rupture – to those of the aramid and glass epoxy composites. The mechanical properties of the hybrid composites being inferior to those of the aramid epoxy composites suggest that there is no advantage in using glass fibres to partially replace aramid fibres in achieving hybrid composites. © The Author(s) 2025
Non-linear thermal stability and free vibration behavior of sandwich beams with auxetic re-entrant aluminum cores and graphene origami-enhanced facings
(Elsevier Ltd, 2025) Shashiraj; Pitchaimani, J.; Kattimani, S.
Revolutionizing advanced sandwich structures, this study delves into the non-linear thermal stability behavior and free vibration characteristics of auxetic aluminum re-entrant core sandwich beams enhanced with graphene origami (GOri) metamaterial facings, subjected to spatially varying thermal environment. The sandwich beams are modeled as layered structures incorporating complex geometric non-linearities, using a higher-order shear deformation framework and non-linear strain–displacement kinematics based on von Kármán assumptions. The governing equations of motion are addressed through the Ritz formulation, enabling an in-depth investigation of how variations in graphene origami layout, concentration, and fold geometry within the face sheets influence the structural performance. Additionally, the influence of various core Poisson's ratio configurations-negative (NPR), zero (ZPR), and positive (PPR)-along with the effects of core angle and thickness ratio, are systematically explored. The results highlight that core topology critically influences post-buckling resistance and non-linear vibrational characteristics. Furthermore, the integration of graphene origami significantly enhances stiffness and structural stability, demonstrating its potential for next-generation aerospace, automotive, and high-performance engineering applications. To the best of the authors’ knowledge, this is the first study to explore the coupled effects of auxetic re-entrant aluminum cores and graphene origami-enhanced facings on the non-linear thermal and dynamic behavior of sandwich beams. © 2025 Elsevier Ltd
Non-linear transient vibration response of graphene origami enhanced metamaterial beams under spatially-varying temperature distributions
(Elsevier Ltd, 2025) Shashiraj; Pitchaimani, J.; Kattimani, S.
Understanding the dynamic behavior of advanced materials under varying conditions is crucial for the development of resilient and efficient structural systems. This research investigates the non-linear transient response of auxetic metamaterial beams enhanced with graphene origami under spatially varying non-uniform thermal environment. Using Timoshenko beam theory with von-Kármánn type non-linear strain–displacement relations, graphene origami beams are modeled as layered structures. The equilibrium equations are solved using the Ritz method, with a focus on how different graphene origami distribution patterns, content levels, and folding degrees influence the transient response under various time-dependent forces. Non-linear motion equations are solved using the Newmark-Beta method. This study evaluates the impact of five distinct non-uniform temperature distributions, seven types of time-dependent loadings, three boundary conditions, and three configurations of graphene origami distribution on the vibration characteristics. Results indicate that parabolic temperature distributions with peak temperatures at the beam ends lead to substantially decreased dynamic deflections. This research provides valuable insights into the structural dynamics of graphene origami-enhanced metamaterial beams within complex thermal environments, highlighting the considerable influence of spatial temperature variations along the length of the beam. © 2025
Nonlinear buckling and free vibration analysis of auxetic graphene origami composite beams under nonuniform thermal environment
(Taylor and Francis Ltd., 2025) Shashiraj; Pitchaimani, J.; Kattimani, S.
This study examines the thermo-mechanical behavior of auxetic metamaterial beams enhanced by graphene origami (GOri) under spatially varying nonuniform temperature distributions (SVTD). Utilizing Timoshenko beam theory considering von-Kármánn type nonlinear strain–displacement relationship, GOri beams are modeled as layered structures. The Ritz method is employed to solve equilibrium equations, analyzing the impact of GOri distribution patterns, content, and folding degree on post-buckling and vibration paths. The effects of five SVTDs, three end conditions, and three GOri distribution patterns on buckling, post-buckling behavior, and nonlinear free vibration characteristics are explored. Findings reveal that the parabolic temperature distribution with peak temperatures at beam ends (P-MAE) results in higher critical temperatures and nonlinear free vibration frequencies. This research provides crucial insights into the design and optimization of GOri-enabled metamaterial structures in complex thermal environments, highlighting the significant influence of nonuniform temperature distributions along the beam’s length. © 2024 Taylor & Francis Group, LLC.
Relation between water absorption and mechanical properties of flax 3D braided yarn woven fabric PLA bio-degradable composites
(SAGE Publications Inc., 2024) Kanakannavar, S.; Pitchaimani, J.
Natural fibre (flax) plain type of woven fabric is developed by using solid braided yarn and is utilised as filler material and PLA (polylactic acid) as a matrix. Solution casting is then used to create sheets of pure PLA and flax fabric–PLA. Composites are manufactured by sheets sequencing technique using the hot compression moulding method. Water absorption, thickness swelling and flexural tests are performed in loading directions of warp and weft of the composites. Results revealed that the absorption of water and swelling of thickness are enriched with an addition of flax fabric. The weft direction loaded composite displayed greater values of water uptake and thickness swelling. The warp direction loaded composites demonstrated the highest flexural strength (92.3 MPa) and modulus (4.5 GPa) compared to weft direction loaded composites. These values are decreased after water absorption. © The Author(s) 2024.
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.