Faculty Publications
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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 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 Vibro-acoustic behaviour of functionally graded graphene reinforced polymer nanocomposites(American Institute of Physics Inc. subs@aip.org, 2020) Pious, D.; Jacob, J.; George, N.; Bhagat, V.; Chacko, T.; Jeyaraj, P.This study conducts an investigation into the vibro-acoustic behavior of polymer nano composites reinforced with functionally graded graphene. The numerical analysis is conducted using both finite element method and Rayleigh integral. Free and forced vibration characteristics are conducted to understand the sound characteristics in depth. The influence of various parameters such as type of functional grading, loading and boundary conditions are also observed. Results shows that natural frequency of a structure is heavily dependent on the type of functional grading of the structure, while the mode shapes are observed to be impervious to these changes. The type of functional grading is also seen to influence the resonant amplitude of vibration and acoustic response. This influence is duly produced in the bandwise calculation of sound power which suggests that FG-X distribution of graphene is to be used for lower frequency levels. © 2020 Author(s).Item Item Buckling and dynamic characteristics of a laminated cylindrical panel under non-uniform thermal load(Techno Press technop2@chollian.net, 2016) Bhagat, V.; Jeyaraj, J.; Murigendrappa, S.M.Buckling and free vibration behavior of a laminated cylindrical panel exposed to non-uniform thermal load is addressed in the present study. The approach comprises of three portions, in the first portion, heat transfer analysis is carried out to compute the non-uniform temperature fields, whereas second portion consists of static analysis wherein stress fields due to thermal load is obtained, and the last portion consists of buckling and prestressed modal analyzes to capture the critical buckling temperature as well as first five natural frequencies and associated mode shapes. Finite element is used to perform the numerical investigation. The detailed parametric study is carried out to analyze the effect of nature of temperature variation across the panel, laminate sequence and structural boundary constraints on the buckling and free vibration behavior. The relation between the buckling temperature of the panel under uniform temperature field and non-uniform temperature field is established using magnification factor. Among four cases considered in this study for position of heat sources, highest magnification factor is observed at the forefront curved edge of the panel where heat source is placed. It is also observed that thermal buckling strength and buckling mode shapes are highly sensitive to nature of temperature field and the effect is significant for the above-mentioned temperature field. Furthermore, it is also observed that the panel with antisymmetric laminate has better buckling strength. Free vibration frequencies and the associated mode shapes are significantly influenced by the non-uniform temperature variations. © 2016 Techno-Press, Ltd.Item Experimental investigation on buckling strength of cylindrical panel: Effect of non-uniform temperature field(Elsevier Ltd, 2018) Bhagat, V.; Jeyaraj, P.Experimental investigation performed to evaluate buckling strength of a cylindrical panel exposed to non-uniform temperature field is presented. A novel experimental set-up developed in-house is used to evaluate buckling strength of a cylindrical panel made of Aluminum. Influence of nature of non-uniform temperature variation, structural boundary conditions and panel aspect ratio on buckling strength is investigated experimentally. Experimental results reveals that effect of nature of temperature field, resulting from the location of heat source, on buckling strength is significant. It is also observed that buckling strength is less when the least stiffness area of the panel is exposed to peak temperature of a particular temperature field. Similarly, CCCC boundary constraints results in high thermal stress which lowers the buckling strength of the panel as compared to CCFC boundary constraints. Temperature-deflection plot and corresponding buckling strength evaluated experimentally are compared with those obtained using non-linear finite element analysis, taking into account the initial geometric imperfection. © 2017 Elsevier LtdItem Structural behavior of fg-cnt cylindrical panel: Influence of non-uniform temperature field(Institute for Problems in Mechanical Engineering, Russian Academy of Sciences, 2020) Bhagat, V.; Jeyaraj, J.In this study, the influence of non-uniform temperature field and temperature-dependent properties on buckling and free vibration behavior of functionally graded carbon nanotube (FG-CNT) reinforced composite cylindrical panel is investigated. For the structural analysis, the finite element method and modal assurance criterion (MAC) analysis are performed. It is found that the temperature-dependent properties and nature of temperature variation fields affect the thermal buckling strength of the panel greatly. The results from MAC analysis reveals that the influence of temperature and nature of temperature variation on buckling and free vibration modes are significant. Further, it is also found that variations in frequencies and associated modes are significant at a temperature closer to buckling temperature. © 2020, Peter the Great St. Petersburg Polytechnic UniversityItem Meta-heuristic optimization of buckling and fundamental frequency of laminated cylindrical panel under graded temperature fields(SAGE Publications Ltd, 2021) Bhagat, V.; Jeyaraj, J.This research deals with the optimization of buckling and fundamental frequency of a cylindrical panel under various heating conditions, which varies across the surface of the panel. A multi-objective design indicator (MODI) is derived with fiber orientations as a design variable. Finite element analysis is used to calculate temperature variation according to the nature of heating, buckling temperature, and fundamental frequency. In this study, scientific computing software is used to incorporate the finite element method with artificial neural network and particle swarm optimization technique. Five different heating cases, including uniform temperature cases, are considered. It is observed from the analysis that the in-plane temperature field of non-uniform type has a significant influence on the buckling and vibration characteristics of the panel. Further, it is observed that panel with lamination scheme of (Formula presented.) gives the higher value of MODI max compared to other lamination schemes considered. © The Author(s) 2020.