Shell Theory Research Articles

VST RESIDUAL LIFE ESTIMATION ALGORITHM BASED ON LOW-CYCLE LOADING CRITERION IN REAL TIME

Due to the significant wear and tear of oil and petroleum product tanks in Russia, there is a need for continuous monitoring of their technical condition. The article provides an overview and analysis of methods for assessing the stress-strain state of the tank wall. The advantages and disadvantages of these methods were identified, as well as the possibility of assessing the stress-strain state of the tank in real time was justified. Calculations of ring stresses were made according to the moment-free theory of shells, calculation of equivalent Von-Mises stresses in ANSYS medium. An analysis of calculations was carried out, the conclusions of which are consistent with the literature data. As a result of the application of various shell theories, production faces a dilemma - or the ability to get operational, but less accurate results and predictions, or use strain gauges to determine wall stresses, or use additional tools in the form of 3D scanning of the tank surface with subsequent processing of data and transfer of the obtained model to the FEA-environment to detect equivalent stresses by Von-Mises, while any efficiency of the process is lost. Strain gauges are one of the effective means of assessing the stress-strain state of the tank wall, but their calibration is not an easy task. The existing diagnostic tools do not allow to estimate the residual wall life by low-cycle loading in real time. An algorithm is proposed for estimating the residual life of the RVS according to the criterion of low-cycle loading in real time, which allows detecting potential problems in advance, maintaining the tank in a timely manner, while reducing the risk of an accident and subsequent more expensive repairs, and promptly taking measures in case of an emergency. The developed algorithm can be used for continuous tank diagnostics.

FREE VIBRATIONS OF THIN ELASTIC ORTHOTROPIC CYLINDRICAL PANEL WITH RIGID – CLAMPED EDGE GENERATOR

Using the system of equations corresponding to the classical theory of orthotropic cylindrical shells, the free vibrations of thin elastic orthotropic cylindrical panel with rigid – clamped edge generator are investigated. In order to calculate the natural frequencies and to identify the respective natural modes, the generalized Kantorovich-Vlasov method of reduction to ordinary differential equations is used. Dispersion equations for finding the natural frequencies of possible types of vibrations are derived. An asymptotic relation between the dispersion equations of the problem at hand and the analogous problem for a cantilever rectangular plate is established. An algorithm for separating possible boundary vibrations is presented. As an example, the values of dimensionless characteristics of natural frequencies are derived for an orthotropic cylindrical panel.

Analytical method for a tunnel with periodically jointed lining in the poroelastic soil under seismic waves

In this study, a longitudinal equivalent periodic shell (LEPS) model and corresponding continuous joint model are proposed for the periodically jointed lining (PJL) tunnel. Based on the LEPS model for the PJL tunnel, an analytical method for the PJL tunnel under seismic waves is established. The surrounding soil of the PJL tunnel is assumed to be the poroelastic medium, and described by the Biot's theory. The lining of the PJL tunnel is assumed to be composed of a series of lining rings linked periodically by ring joints along the longitudinal direction, which are simplified as a LEPS and described by the cylindrical shell theory. Due to the periodicity of the LEPS lining, the tunnel-soil system is treated as a periodic structure in this study. Based on the periodicity condition for the tunnel-soil system as well as the wave function expansion method, the representation for the scattering wave field in the soil is established. By using the aforementioned cylindrical shell theory and Fourier series expansion method, the Fourier space equations of motion and convolution type constitutive relations for the LEPS lining are derived. By using the lining-soil continuity conditions, the Fourier space equations of motion and convolution type constitutive relations for the LEPS lining as well as the representation for the wave field in the soil, the coupled equations for the tunnel-soil system are established, with which the Fourier components of the displacements of the LEPS lining and wave function coefficients for the scattering waves in soil can be solved for. Numerical results indicate that the presence of the ring joint in the LEPS lining of the tunnel will affect the distribution of the internal forces in the lining considerably, and it will also enhance the maximum internal forces occurring in the lining.

A new analytical approach for nonlinear buckling and postbuckling of torsion-loaded FG-CNTRC sandwich toroidal shell segments with corrugated core in thermal environments

The design of the torsion-loaded toroidal shell segment with two functionally graded carbon nanotube-reinforced composite (FG-CNTRC) coatings and the corrugated core is presented. Round and trapezoidal shapes of the corrugated core are considered. A homogenization model for the corrugated core is applied to predict the stiffnesses of the corrugated core. The total potential energy equation, according to the Donnell shell theory, is established. The Ritz energy method is applied to determine the expressions of the buckling and postbuckling responses. The numerical investigations present the significantly beneficial effects of FG-CNTRC coatings and corrugated core on the buckling responses of the shells.

Study of Gap Flow Effects on Sound Transmission Through a Micro-Perforated Sandwich Cylindrical Shell Excited by a Plane Wave

This paper presents a theoretical model to study sound transmission through a micro-perforated double-walled sandwich cylindrical shell with emphasis on the potential of internal gap flow to improve the sound insulation performance. This model adopts Donnell’s thin shell theory to govern the shell motions and a simplified model based on Biot’s theory to describe sound propagation in the porous lining. The mean acoustic particle velocity model with the grazing flow effect is applied to define the coupling condition between the fluid medium and the perforated shell. Transmission loss (TL) through the configuration with one gap flow is numerically calculated using the mode superposition method when subjected to an oblique plane wave in the presence of an external mean flow. Results reveal that the gap flow in the opposite direction to the external flow would elevate the mid-frequency TL. Gap depth has a complicated effect on TL since it influences the aerodynamic damping of the gap flow and sound dissipation in the porous layer. The average TL in 20–20[Formula: see text]000[Formula: see text]Hz is then optimized with a genetic algorithm, and an increase of 17.82 dB is finally achieved. The possibility of tuning the structural sound insulation performance by the gap flow has been verified.

Elasticity and stability of corrugated conical shells with diverse orthotropy

Curved thin-walled structures have attracted significant attention within engineering communities thanks to their remarkable properties, including high load-bearing capacity, tailorable directional stiffness, adaptability, and lightweight characteristics. The geometric intricacies of these structures not only influence their mechanical behavior but also provide a vast design space for exploring new frontiers in structural development. This study investigated a unique form of curved thin-walled structure, namely the corrugated annular conical shell, which exhibits diverse degrees of cylindrical orthotropy across various corrugation patterns. An analytical model was formulated based on the minimum total potential energy principle and first-order shear deformable shell theory to predict the non-monotonous force-deflection relationships and non-uniform stress distributions in corrugated conical shells when axially loaded under compression. Within this novel framework, the local undulation shape, corrugation pitch, and amplitude emerged as influential determinants of the responses of corrugated shells, intrinsically intertwined with the polar and shear orthotropy ratios. The accuracy of our analytical model was verified by comparing its results to those obtained using the finite element method and experimental measurements. A machine learning method was employed to classify the stability behaviors of corrugated annular conical shells and derive comprehensive design maps for the first time. Corrugated annular conical shells hold enticing potential for applications as adaptive spring units or building blocks for more sophisticated architectural metamaterials.

Low-velocity impact resistance of all composite cylindrical shell panels with a foam filled honeycomb core: Theoretical and experimental investigation

The low-velocity impact resistance of all composite cylindrical shell panels (CCSPs) with a foam filled honeycomb core (FFCHC) is studied experimentally and theoretically. Initially, a dynamical model of the FFCHC-CCSPs is proposed, with the equivalent material properties of the core being determined by combining the Hamilton equivalence theory and the Gibson theory. By using the virtual work principle and quasi-static method, together with the von Karman's theory and the high order shear deformation shell theory, the constitutive relationship related to each damage case is derived. Also, by considering the influence of collapse of the FFCHC, the failure criteria and damage modes are modified. The impact displacement, load and impact energy absorption are solved by using the elastoplastic contact principle and energy principle. Several numerical results from the literature are employed for preliminary validation of the model. Furthermore, the FFCHC-CCSP specimens with and without polyurethane foam are fabricated and the detailed measurements associated with different impact energies are performed to provide a solid validation of the present model as well as to evaluate the structural impact resistance. Finally, the influences of the thickness of FFCHC, wall thickness and side length of honeycomb cell and density of foam on the impact resistance of the FFCHC-CCSP structures are discussed, with some useful conclusions being refined for better impact suppression design and manufacture of such advanced shells.

R.C.C Shell Structure Design of Selected Head Cap Shape

Abstract: A shell structure is a thin structure composed of curved sheets of material, so that Shell structures are inspired from natural element named “SHELL”. A thin curved member or slab usually of reinforced concrete that function as tension member and shell. The waviness plays an important role in the structural behavior realizing a spatial form. Some of natural elements like eggshell, seashell, fruit shells (walnut) etc are showing shell structure properties. The present reinforced concrete shells as a very efficient structure, spanning wide, architectonically beautiful, relevant and valuable structural solution. Shell structures are very attractive lightweight structures, which are especially suited to Architectural building, industrial application, commercial projects etc.. The actual design of shells, involves theories of shells and the use of appropriate codes of practice. Types of curved shell like Parabolic, Hyperbolic or Cylindrical members are often said to act as tension rigidity hence called tensile members. For achieving the optimized load capability and flexural strength of such an element in form of shell covering structure is checked in for M30 grade concrete. Tensile shell members are structural edifice that caries only tension and without buckling or bending. Tensile structures are the most common type of thin-shell structures used worldwide from past decades. The profile and aspect of structure used are unlike for loading conditions, geographical locations and Architecture design differs as such as horizontal, sloping or curved member (dome and shell member). In this research work the tensile shell (plate) structure is designed in the form of beam and as grid shell slab element (plate). After then load has been applied for analysis via software tool i.e. STAAD Pro. The types of load assigned dead and live loads. The Design code specifications for curved shell member in IS: 2210–1994, IS 2204-1962 “Code of practice for construction of reinforced concrete shell roof” [CED 13: Building Construction Practices including Painting, Varnishing and Allied Finishing] and the load case criteria is to be as per IS: 875(2)–2000. RCC design specifications as per IS: 456–2000

Simulation and Optimization of Hemispherical Resonator's Equivalent Bottom Angle for Frequency-Splitting Suppression.

As an inertial sensor with excellent performance, the hemispherical resonator gyro is widely used in aerospace, weapon navigation and other fields due to its advantages of high precision, high reliability, and long life. Due to the uneven distributions of material properties and mass of the resonator in the circumferential direction, the frequencies of the two 4-antinodes vibration modes (operational mode) of resonator in different directions are different, which is called frequency splitting. Frequency splitting is the main error source affecting the accuracy of the hemispherical resonator gyro and must be suppressed. The frequency splitting is related to the structure of the resonator. For the planar-electrode-type hemispherical resonator gyro, in order to suppress the frequency splitting from the structure, improve the accuracy of the hemispherical resonator gyro, and determine and optimize the equivalent bottom angle parameters of the hemispherical resonator, this paper starts from the thin shell theory, and the 4-antinodes vibration mode and waveform precession model of the hemispherical resonator are researched. The effect of the equivalent bottom angle on the 4-antinodes vibration mode frequency value under different boundary conditions is theoretically analyzed and simulated. The simulation results show that the equivalent bottom angle affects the 4-antinodes vibration mode of the hemispherical resonator through radial constraints. The hemispherical resonator with mid-surface radius R=15 mm and shell thickness h=1 mm is the optimization object, and the stem diameter D and fillet radius R1 are experimental factors, with the 4-antinodes vibration mode frequency value and mass sensitivity factor as the response indexes. The central composite design is carried out to optimize the equivalent bottom angle parameters. The optimized structural parameters are: stem diameter D=7 mm, fillet radii R1=1 mm, R2=0.8 mm. The simulation results show that the 4-antinodes vibration mode frequency value is 5441.761 Hz, and the mass sensitivity factor is 3.91 Hz/mg, which meets the working and excitation requirements wonderfully. This research will provide guidance and reference for improving the accuracy of the hemispherical resonator gyro.

Observation and Thermodynamic Analysis of Reversible Fluid Isobars in Isolated Single Digit Nanopore Carbon Nanotubes

Recent interest in one-dimensionally confined fluids, where confinement approaches molecular dimensions, has demonstrated exceptionally high fluxes from slip flow and large distortions of fluid phase boundaries [1,2]. The Center for Enhanced Nanofluidic Transport (CENT) was recently formed as an intellectual hub for studying extreme fluid confinement in what we label Single Digit Nanopores (SDNs). To this end, in this work, we note that predicting such phenomena for a given conduit dimension has been confounded by a dearth of fundamental thermodynamic measurements and analysis as a function of confinement diameter and wall composition. Herein, we utilize Raman spectroscopy and carbon nanotubes with diameters less than 3 nm to identify and study newly observed, thermally driven, fluid adsorbed phases under conditions at constant ambient pressure, tracing what we label a fluid isobar as a function of temperature. We show that the Raman radial breathing(-like) vibrational modes (RBLMs) can serve as fluid sensors to trace the dependence of the fluid isobar and allow study of basic thermodynamics of fluid phase transition as a function of conduit curvature and confinement volume. We study fluids on the exterior and interior of double- and single- walled carbon nanotubes spanning 0.9 to 3.3 nm in diameter, showing that the fluid location can be disambiguated on double walled tubes by using an adaptation of elastic shell theory that allows deconvolution of inner and outer shell frequencies with fluid location. We find that the RBLM FWHM systematically changes as a unique signature of the location of the fluid phase near the CNT wall. A Buckingham potential is used along with electron diffraction assigned DWNT to provide a high accuracy estimate of the carbon-carbon coupling constant for two elastic shells, an important structural parameter for DWNT. The thermodynamic analysis of isobars measured for more than 25 CNTs under various environmental conditions is conducted by comparison to a new fluid equation of state that provides a continuum description of the fluid isobar under confinement. Our work sets forth a new and reliable approach for studying phase change of different fluids in large numbers of isolated single digit nanopores that may inform the refinement of fluid force fields and motivate theoretical refinements to the calculation of thermodynamic properties under confinement.[1] S. Faucher, N. Aluru, M. Z. Bazant, D. Blankschtein, A. H. Brozena, J. Cumings, J. Pedro De Souza, M. Elimelech, R. Epsztein, J. T. Fourkas, A. G. Rajan, H. J. Kulik, A. Levy, A. Majumdar, C. Martin, M. McEldrew, R. P. Misra, A. Noy, T. A. Pham, M. Reed, E. Schwegler, Z. Siwy, Y. Wang, M. S. Strano. Critical Knowledge Gaps in Mass Transport through Single-Digit Nanopores: A Review and Perspective. J. Phys. Chem. C 123, 21309–21326 (2019).[2] K. V. Agrawal, S. Shimizu, L. W. Drahushuk, D. Kilcoyne, M. S. Strano. Observation of extreme phase transition temperatures of water confined inside isolated carbon nanotubes. Nat. Nanotechnol. 12, 267–273 (2017)

On dynamic of imperfect GNP nanocomposite joined hemisphere-cylinder shells on Winkler foundation

This paper aims to analyze the frequencies related to the poriferous nanocomposite joined hemisphere-cylinder shells (JHCS) resting on the Winkler foundation for the first time. In detail, the Winkler foundation is used to model the soil’s behavior surrounding the JHCS. Graphene nanoplatelet (GNP) is a nano-size material that enhances a matrix to make GNP nanocomposites (GNPNs). Additionally, nine different functionally graded (FG) distribution forms along the thickness of the JHCS are used to mark the efficiency of GNP through the GNPN. In addition, two distribution models along the thickness of the JHCS, covering FG and uniform models, are implemented to address the effect of the porosity along the GNPN. Supplementarily, via joining Donnell’s shell and first shear deformation theories, the primary equations of the JHCS are determined. Addedly, Hamilton’s principle finds the fundamental motion equations (FMEs) of the JHCS. The generalized differential quadrature scheme discretizes the FMEs, boundary, and joining equations. Next, via eigenvalue determination, the frequencies of the system are discovered. Finally, the influences correlated with physical values, FG forms of the GNP, edge cases, porosity models, and Winkler foundation on the frequencies correlated with the poriferous nanocomposite JHCS are evaluated.

Investigation on Free Vibration of Rotating Cylindrical Shells with Variable Thickness

In order to improve the performance and efficiency of the rotating cylindrical shell (RCS), one of the effective ways reduces the mass of the RCS. The scientific and effective method is to design the variable thickness of RCS (VTRCS) along the axial direction in response to this demand. Then, the vibration traveling wave characteristics of VTRCS are investigated by Chebyshev–Ritz method. The displacement field of the cylindrical shell is expanded in the form of the product of the Chebyshev polynomial and the boundary function. The kinetic and potential energies of the VTRCS are calculated based on the Sanders shell theory considering the effects of Coriolis forces and centrifugal forces. Also, the frequency equation of the VTRCS is obtained according to the Ritz method. The accuracy of the modeling method is verified by comparing the present results with literature that had done, and the convergence of the calculated results is studied. Finally, the free-vibration traveling wave characteristics of the VTRCS in different thickness variations are compared, and the parameters such as the rotational speed, thickness variation parameters, and aspect ratio on the free-vibration traveling wave characteristics of the VTRCS are discussed. The influence of thickness variation on the vibration characteristics is analyzed, which has significance for the lightweight design for VTRCS.

Nonlinear Oscillations and Buckling Prediction for Shallow Convex Shells

Since 2010, the testing of thin-walled shallow shells has revealed that the ultimate internal stresses, under which the shells lose their stability (collapse), appeared to be lower than those predicted by the buckling theory used in American and European standards. The existing norms are based on the static theory of shallow shells proposed in 1930 with stable solutions for thin-walled structures within the nonlinear theory. These stable solutions differ significantly from the forms of equilibrium common to small initial loads. The minimum load, under which an alternative form of equilibrium exists, was used as the ultimate load. In the 1970s, this approach was proved to be unacceptable for complex loadings that were not a part of the real world in the past but are now the case with thinner products operated under complex conditions. Therefore, the initial theories on bearing capacity evaluations must be revisited. The new theory could be built on the basis of recent mathematical results establishing that the estimates made per two schemes (three-dimensional dynamic theory of elasticity and dynamic theory of shallow convex shells) were asymptotically close. Green's special function is introduced to convert the Foppl-von Karman system into a resolving integro-differential equation. The obtained nonlinear equation allows for the separation of variables and has numerous time-periodic solutions that satisfy the Duffing equation with a "soft spring". Numerical analysis enables determining the amplitude and period of oscillations depending on the properties of Green's function. This paper reviews an experimental setup in which oscillations are generated with the probing load directed normally to the surface of the shell. The experimental measurements of the resonance displacements as a function of coordinates and time enable the calculation of the safety factor for the bearing capacity of the structure using the non-destructive method under operating conditions.

Free Vibration Analyses of Stiffened Functionally Graded Graphene-Reinforced Composite Multilayer Cylindrical Panel

In this paper, the free vibration response of a stiffened functionally graded graphene nanoplatelet (GPL)-reinforced composite multilayer cylindrical shell panel is studied for the first time. The shell is stiffened by both stringers and rings. Additionally, the effect of reinforcing the shell panel, ring and stinger with GPLs is independently studied. Halpin–Tsai relations are employed to evaluate the mechanical properties of the shell panel, rings and stringers. The first-order shear deformation shell theory, accompanied by the Lekhnitsky smeared stiffener model, using the numerical finite element method and Hamilton principle, is employed to develop the governing motion equations of the shell panel. Four different types of GPL patterns, including FG-A, FG-X, FG-O and UD, are assumed across the thickness of the shell panel, rings and stringers. The effects of different factors, including various weight fractions and patterns of GPLs nanofillers, the geometry of the shell panel and stiffeners and two displacement boundary conditions, on the natural frequencies of the shell panel, have been studied.

On the Static Instability of FG-GNP-Reinforced Composite Cylindrical Shells Under Thermo-Mechanical Loading

The nonlinear buckling response of laminated composite cylindrical shells reinforced with graphene nanoplatelets (GNPs) is studied in this paper. The functionally graded (FG) shell reinforced by GNPs is analytically studied under external pressure and uniform temperature rise loadings. It is also assumed that the GNP-reinforced laminated composite shell is in contact with an elastic foundation. Various types of profiles are employed for the GNP distribution patterns in the shell thickness including 10 nanocomposite layers. The nonlinear strain-displacement relations of the shallow cylindrical panel are established utilizing the third-order shear deformation shell theory. Governing equilibrium equations of the laminated GNP-reinforced composite shell are formulated employing the principle of virtual displacement. The coupled system of nonlinear differential equations is solved analytically for the hinged–hinged and fixed–fixed boundaries of the shell using a perturbation-based technique. Correctness of presented formulations and obtained solutions is proved by comparisons with results from previous studies for an isotropic cylindrical shell. Novel numerical results reveal that the material properties, geometrical characteristics and load parameters significantly affect on the buckling behavior of laminated composite cylindrical shells.

Theoretical modeling of the pre-cutting system performance for the tunnel face stability in very weak rock masses

By forming continuous pre-lining around the tunnel's perimeter, pre-cutting is a recognized tunneling technique that enables full-face excavation of a tunnel even in unfavorable ground conditions. In this study, a theoretical method is put out to simulate the performance of this kind of pre-support in squeezing conditions. The loading distribution on the pre-cutting shells is determined for this purpose using the LDP of an unsupported tunnel, and the non-linear stiffness of the pre-cutting shell is then determined using the shell theory. The convergence confinement method is used to calculate how much the pre-supported tunnel isdeformed. The non-uniform loading distribution also results in the tangential and longitudinal bending moments on the pre-cutting shell. To show the effectiveness of pre-cutting shells in extremesqueezingconditions, several examples are solved. As a result, a few graphs for the preliminarydesign of a tunnel using this technique are given. The graphs show the overall tunnel displacement for various pre-cutting shells under various geological conditions. The outcomes demonstrate good agreement between FALC 3D resultsand the ones by thesuggested analytical model. A preliminary design can be made using the assessment of the proposed methodonthe loads on the pre-cutting system.

Nonlinear dynamics of bolted joined conical-cylindrical shells considering displacement-dependent characteristics

This paper investigates the nonlinear dynamic characteristics of joined conical-cylindrical shells (JCCSs) with bolt connection for the first time. In the process of developing mechanical model of the bolt connection, the displacement-dependent stiffness and damping are taken into account, which could simulate the change of the contact state at the connection interface under different excitations. Both theoretical and experimental studies are performed to illustrate the nonlinear vibration behaviors of the bolted JCCSs. Successive uniform distributed artificial springs between the conical and cylindrical shells are adopted to simulate the rigid joint of the two shells. Donnell's shell theory is employed in theoretical modeling, and the governing equation is obtained by the Lagrange equation. The displacement admissible function applied in the research is Chebyshev polynomial. By comparison with existing literature and experimental data, the accuracy of present theoretical model is validated. It is found that both theory and experiment show a dynamic softening phenomenon with the increase of excitation level. Taking the displacement-dependent characteristics in bolt connection zone into consideration can effectively illustrate this soft phenomenon. The established model is capable of predicting the nonlinear vibration characteristics of JCCSs with bolt connection.

Buckling Analysis of Grid-stiffened Composite Cylindrical Shell

An energy based smeared stiffener model is developed to obtain equivalent stiffness coefficients of a general grid-stiffened composite cylindrical shell. These equivalent stiffness coefficients are used in the Ritz buckling analysis of the shell. Transverse shear properties are important in a stiffened shell and results are obtained for First order Shear Deformation Theory (FSDT) as well as for Classical Laminated Shell Theory (CLST). Parametric study is carried out to find out the effects of various design parameters on specific buckling load of the shell.

Structural optimization of an encased bi-material FGP-GNF pipeline-liner system with novel polyhedral configurations

This article proposes a novel thin-walled polyhedral functionally graded porous (FGP) liner consolidated by graphene nanofillers (GNF) to rehabilitate the cracked pipeline. A buckle propagation may occur since the liner is subjected to hydrostatic pressure and temperature variational field simultaneously. A cosine function is developed to describe the deformed shape of the liner. Both pores and the GNF are distributed symmetrically on the cross-section of the liner, which also has a polyhedral profile to improve its bending stiffness. The nonlinear equilibrium equations are accurately obtained by introducing the thin-walled shell theory and the principle of minimum potential energy. The critical buckling pressure is obtained by solving the nonlinear equilibrium equations. Analytical solutions are compared successfully with other closed-form results to accomplish the verification when the FGP-GNF polyhedral liner reduces to an isotropic circular one. Furthermore, one improvement factor is proposed to analyze the effect of different polyhedral shapes on the buckling pressure of the encased polyhedral FGP-GNF liner. Finally, parameters are evaluated to further understand the buckling behavior of the FGP-GNF polyhedral liner, including the number of polygons, porosity coefficient, mass fraction, geometric shape of the GNF, radius-to-thickness ratio, temperature field, etc.

Vibration Control of Composite Thick Shells Using Magnetostrictive Material and Higher Order Shear Deformation Theory

Analytical solutions of laminated composite shells with embedded actuating layers are presented in this study. The actuating layers are used to control natural vibration of laminated composite shell panels. The first order shear deformation theory (FSDT) and higher order shear deformation theory (HSDT) for shells are used to represent the shell kinematics and equations of motion. The exact solution for symmetric laminated shells with embedded actuating layers under simply supported boundary conditions is obtained using the Navier solution procedure. Negative velocity feedback control is used. The parametric effect of the position of the magnetostrictive layers, material properties and control parameters on the vibration suppression are investigated in detail. It is found that (i) the shortest vibration suppression time is achieved by placing the actuating layers farthest from the neutral axis (ii) using thinner smart material layers leads to better vibration attenuation characteristics and, (iii) the vibration suppression time is longer for a lower value of the feedback control coefficient. For thicker shells HSDT predicts larger amplitude of vibration and longer vibration suppression time as compared to FSDT predictions.