Faculty Publications
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Item Mechanical, Dynamic Mechanical and Vibration Behavior of Nanoclay Dispersed Natural Fiber Hybrid Intra-ply Woven Fabric Composite(Springer Science and Business Media B.V., 2016) RAJESH, M.; Jeyaraj, P.; Nagarajan, N.Influence of nanoclay dispersion on mechanical, dynamic mechanical and free vibration characteristics of basket type intra-ply woven banana/jute (banana yarn-weft direction, jute yarn-warp direction) hybrid polyester composite has been investigated. Results revealed that loading of nanoclay enhances the mechanical properties of the composite significantly as it improves the adhesion between fiber and matrix. Dynamic mechanical analysis result reveals that nanoclay addition significantly increases the storage modulus and glass transition temperature of the intra-ply hybrid composite. From free vibration studies, carried out on laminated beam like structures, it is found that the natural frequency of the composite laminate increases till 2 wt% of nanoclay while the modal damping increases when the wt% of nanoclay is more than 2. However, due to the agglomeration effect of nanoclay the properties are not improved for nanoclay loading beyond 2 wt%. © 2016, Springer Science+Business Media Singapore.Item Experimental investigation on vibration and static deflection of 3D printed functionally graded triply periodic minimal surface beams(Elsevier, 2025) Kurup, M.; Jeyaraj, P.This research work presents a comprehensive experimental investigation on free vibration and static deflection behavior of functionally graded triply periodic minimal surface (FG-TPMS) beams. The grading in these beams is obtained by changing the wall thickness of the TPMS unit cell layer wise. Polylactic acid filament is used to print the samples through the fused filament fabrication approach. The study explores the influence of various geometrical dimensions, with specific emphasis on the unit cell size and its graded pattern through the thickness. Four primary lattice cells, namely, gyroid, primitive, diamond, and IWP (I-graph & wrapped package-graph), are chosen for analysis. The findings from this study provide valuable insights, demonstrating that a specific lattice cell pattern with appropriate grading has the potential to enhance the vibration properties and deflection characteristics of 3D-printed samples. This knowledge is crucial for designing lightweight and efficient structures, particularly in the context of advancements in additive manufacturing technologies. © 2026 Elsevier Inc. All rights reserved..Item Static behavior of FG-CNT polymer nano composite plate under elevated non-uniform temperature fields(Elsevier Ltd, 2013) Jeyaraj, P.; Rajkumar, I.In this paper, static behavior of functionally graded carbon nanotube reinforced polymer composite plate under non uniform elevated temperature fields has been investigated using finite element method. The effective material properties of the composite plate are obtained using the extended rule of mixture along with carbon nanotube efficiency parameters (to include size-dependent material properties). Parameter studies are carried out to analyze influence of boundary conditions of the plate, type of functional grading of the carbon nanotube and type of non uniform thermal loading on static behavior of the functionally graded carbon nanotube reinforced composite plate. It is found that static behavior of the composite plate has been significantly influenced by nature of temperature field and nature of functional grading of carbon nanotubes. Static bending deflection of the plate increases with volume fraction of the carbon nanotube except for unsymmetrical distribution of carbon nanotube. © 2013 The Authors. Published by Elsevier Ltd.Item Bending, buckling and free vibration characteristics of FG-CNT-reinforced polymer composite beam under non-uniform thermal load(SAGE Publications Ltd, 2015) Mayandi, K.; Jeyaraj, P.Bending, buckling and free vibration behaviors of functionally graded (FG) carbon nanotube (CNT)-reinforced polymer composite beam under different non-uniform thermal loads have been analyzed using finite element method. Extended rule of mixture is used to obtain effective material property of the composite. Four different types of FG beam exposed to four different assumed one-dimensional temperature distributions along the length of the beam are analyzed. Parameters studies are carried out to investigate influences of the volume fraction of the carbon nanotube, functional grading and the nature of temperature variation on bending, buckling and free vibration characteristics. It is found that bending deflection reduces with increase in volume fraction of the CNT except for unsymmetrical functional graded beam. The static bending deflection and deformed shape of the beams are significantly influenced by the nature of temperature field. The critical buckling temperature of the beam with symmetric CNT distribution (where CNTs concentration is far from the neutral axis) is greater than other beams under different temperature fields and its value is less when the beams are exposed to uniform temperature rise above ambient temperature compared to other non-uniform temperature variations. However, the critical buckling temperature is not increasing significantly with increase in volume fraction of the CNT. The fundamental buckling mode shape is not sensitive to the nature of temperature variation but bending amplitude of the buckling mode shape is significantly influenced by functional grading of CNT and volume fraction of the CNT. The natural frequency of the beams reduces significantly with increase in temperature and the free vibration mode shapes are not influenced by temperature rise, nature of temperature variation and volume fraction of the CNT. © 2013 IMechE.Item Free Vibration Characteristics of Banana/Sisal Natural Fibers Reinforced Hybrid Polymer Composite Beam(Elsevier Ltd, 2016) RAJESH, M.; Jeyaraj, P.; Nagarajan, N.Natural fibers having more advantage compared to man-made fiber, such as glass, carbon, Kevlar fiber. But due to the hydrophilic nature of natural fiber gives poor adhesion between fiber-matrix. This will decrease the properties of polymer composite. In this study influence of surface pre-treatment with sodium hydroxide and hybridization effect of natural fiber are investigated on flexural test and free vibration behavior. In this work sisal and banana natural fibers are used in short and random orientations to prepare the polymer composites using compression moulding method. From the experimentation, it is found that chemical treatment improves the mechanical and free vibration properties of polymer composites due to the enhancement of interfacial bond between fiber and matrix as the result of chemical treatment. © 2016 The Authors.Item Buckling and Free Vibration Characteristics of a Uniformly Heated Isotropic Cylindrical Panel(Elsevier Ltd, 2016) Bhagat, V.; Jeyaraj, P.; Murigendrappa, S.M.In this paper buckling and free vibration characteristics of an isotropic cylindrical panel subjected to uniform temperature rise has been investigated using finite element method. The procedure involves the determination of critical buckling temperature, which is followed by modal analysis considering pre-stress due to the thermal field in the cylindrical panel. Detailed studies are carried out to analyze the influence of curvature ratio, thickness ratio and aspect ratio on the critical buckling temperature and free vibration behavior of an isotropic cylindrical panel. It has been found that as the curvature ratio and the thickness ratio increases the thermal buckling strength of the cylindrical panel decreases. It has also been found that free vibration frequencies reduce with an increase in temperature and the reduction is more significant for the lowest frequency mode. It is observed that free vibration mode shapes at ambient temperature changes with an increase in temperature. © 2016 The Authors.Item Effect of Core Topology on Vibro-acoustic Characteristics of Truss Core Sandwich Panels(Elsevier Ltd, 2016) Arunkumar, M.P.; Jeyaraj, P.; Gangadharan, K.V.; Mailan Chinnapandi, M.C.L.This paper presents numerical simulation studies on effect of core topology on vibro-acoustic behaviour of truss core sandwich panels with metal facings. Free and forced vibration responses of the panels are obtained using finite element method based on the equivalent 2-dimensional models. Sound radiation characteristics of the panel are obtained using Rayleigh integral. It is found that influence of nature of core topology on sound radiation is significant in lower frequencies. It is observed that compared to trapezoidal and rectangular core, triangular core is more suitable for low frequency application and also it radiates less sound compare to trapezoidal and rectangular core. © 2016 The Authors.Item Optimization of buckling strength and fundamental frequency of uniformly heated cylindrical panel using PSO(Institute of Electrical and Electronics Engineers Inc., 2017) Bhagat, V.; Jeyaraj, P.; Murigendrappa, S.M.In the present study, thermal buckling and fundamental frequency of symmetrically laminated cylindrical panel is optimized. Fiber orientation is considered as a design variable for the same. Eigenvalue buckling analysis and modal analysis is performed by using finite element method. Particle swarm optimization is used as optimization technique. MATLAB code is generated to integrate finite element method with particle swarm optimization. Finally, the influence of aspect ratio (L/S), curvature ratio (R/S), thickness ratio (R/h), effect of different weighting factors and boundary constraints on the optimum results are investigated. © 2016 IEEE.Item Buckling and Free Vibration Behavior of a Temperature Dependent FG-CNTRC Cylindrical Panel under Thermal Load(Elsevier Ltd, 2018) Bhagat, V.; Jeyaraj, P.; Murigendrappa, S.M.Present study deals with the buckling and free vibration behavior of functionally graded carbon-nanotubes reinforced composite (FG-CNTRC) cylindrical panel exposed to uniform thermal load. Stresses setup due to thermal load and temperature dependent properties influences the buckling and free vibration behavior of the heated structures. Approach employed in the present study consists of static analysis to compute thermal stresses, eigen-value buckling analysis to compute critical buckling temperature and finally modal analysis, taking thermal stresses into account. Influence of different CNTs grading pattern, CNTs volume fraction, geometric parameters, boundary constraints and temperature dependent properties on the buckling strength are investigated. It is observed that hybrid CNTs distribution pattern gives comparatively higher buckling strength and free vibration frequencies. Investigation on free vibration characteristics of the FG-CNTRC panel at elevated temperature signifies that the decline in free vibration frequencies is very drastic at a temperature close to buckling temperature along with temperature dependent properties. c 2017 Elsevier Ltd. All rights reserved. © 2018 Elsevier Ltd.Item Dynamic impact behavior of syntactic foam core sandwich composites(DEStech Publications Inc. info@destechpub.com, 2018) Breunig, P.; Damodaran, V.; Shahapurkar, K.; Waddar, S.; Doddamani, M.; Jeyaraj, P.; Mohan Kumar, G.C.M.; Prabhakar, P.Sandwich composites and syntactic foams have historically been used in many engineering applications to meet the needs of a system. However, there has been minimal effort to take advantage of the weight saving ability of syntactic foams in the cores of sandwich composites, especially with respect to the impact response of the structure. The goal of this experimental study is to investigate the mechanical response and damage mechanisms associated with sandwich composites with syntactic foam cores. The core was manufactured using epoxy resin as the matrix and cenospheres as the reinforcement with varying volume fractions of 0%, 20%, 40%, and 60%. The sandwich composites were manufactured with the vacuum assisted resin transfer molding (VARTM) process. Impact tests were performed on the specimens according to ASTM D7766 at two energy levels: 80J and 160J. The data from the tests was post-processed to gain quantitative understanding of the damage mechanisms present in the specimens. A qualitative understanding was obtained through MicroCT scanning imaging. The analysis showed that increasing the volume fraction of cenospheres in the syntactic foam made the damage mechanism more desirable, even at high energy levels. © 2018 by DEStech Publications, Inc. All rights reserved..