The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
Marco Amabili - One of the best experts on this subject based on the ideXlab platform.
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Non-linear vibration response of functionally graded circular cylindrical Shells subjected to thermo-mechanical loading
Composite Structures, 2019Co-Authors: Amit Yadav, Marco Amabili, Sarat Kumar Panda, Tanish DeyAbstract:Abstract The analysis of the non-linear vibration response is carried out for functionally graded (FG) circular cylindrical Shells subjected to thermal environment along with mechanical in-plane non-uniformly distributed loading along the edges and harmonic radial force. The temperature dependent material properties of the Simply Supported Shell are assumed to vary in the radial direction according to power-law distribution. Based on the first-order shear deformation theory and von-Karman type geometric nonlinearity, the strain-displacement relationships are established for circular cylindrical Shells. The coupled governing equations of motion for functionally graded cylindrical Shells are then derived using Hamilton’s principle. Employing Galerkin’s method, the coupled partial differential equations of motions are reduced to a set of non-linear ordinary differential equations. In order to obtain the free and forced vibration response of the FG Shell, the incremental harmonic balance method, in conjunction with the arc-length method, is used. The non-uniform in-plane loading is converted to Fourier series and the pre-buckling analysis is performed to determine the stress distribution within the Shell. The non-linear frequency-amplitude response is studied to examine the effects of volume fractions of the constituents, static partial edge loadings, thermal loads, and radial periodic loadings.
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stability and vibration of empty and fluid filled circular cylindrical Shells under static and periodic axial loads
International Journal of Solids and Structures, 2003Co-Authors: Francesco Pellicano, Marco AmabiliAbstract:Abstract In the present study, the dynamic stability of Simply Supported, circular cylindrical Shells subjected to dynamic axial loads is analysed. Geometric nonlinearities due to finite-amplitude Shell motion are considered by using the Donnell’s nonlinear shallow-Shell theory. The effect of structural damping is taken into account. A discretization method based on a series expansion involving a relatively large number of linear modes, including axisymmetric and asymmetric modes, and on the Galerkin procedure is developed. Axisymmetric modes are included; indeed, they are essential in simulating the inward deflection of the mean oscillation with respect to the equilibrium position and in describing the axisymmetric deflection due to axial loads. A finite length, Simply Supported Shell is considered; the boundary conditions are satisfied, including the contribution of external axial loads acting at the Shell edges. The effect of a contained liquid is investigated. The linear dynamic stability and nonlinear response are analysed by using continuation techniques and direct simulations.
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Nonlinear dynamics and stability of compressed circular cylindrical Shells
Computational Fluid and Solid Mechanics 2003, 2003Co-Authors: Francesco Pellicano, Marco AmabiliAbstract:Publisher Summary In this chapter, the dynamic stability of Simply Supported, circular cylindrical Shells under periodic axial loads is analyzed. Nonlinearities because of finite-amplitude Shell motion are considered by using the Donnell's nonlinear shallow-Shell theory. A finite length, Simply Supported Shell is considered; the boundary conditions are satisfied, including the contribution of external axial loads acting at the Shell edges. The effect of a contained liquid on the dynamic stability is investigated. The Shell is either empty or completely fluidfilled. An incompressible inviscid fluid is considered and the effect of the dynamic pressure acting on the Shell surface is linearized in the process. The fluid velocity field is described in terms of the velocity potential Ф. To quantify the effect of a contained fluid and the damping, the dynamic critical loads are computed for different excitation frequencies, damping ratios and considering empty and water-filled Shells.
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Large-Amplitude Vibrations of Empty and Fluid-Filled Circular Cylindrical Shells With Imperfections: Theory and Experiments
5th International Symposium on Fluid Structure Interaction Aeroelasticity and Flow Induced Vibration and Noise, 2002Co-Authors: Marco Amabili, M. Pellegrini, Francesco PellicanoAbstract:The large-amplitude response of perfect and imperfect, Simply Supported circular cylindrical Shells to harmonic excitation in the spectral neighbourhood of some of the lowest natural frequencies is investigated. Donnell’s nonlinear shallow-Shell theory is used and the solution is obtained by Galerkin method. Several expansions involving 16 or more natural modes of the Shell are used. The boundary conditions on the radial displacement (Simply Supported Shell at both ends) and the continuity of circumferential displacement are exactly satisfied. The effect of internal quiescent, incompressible and inviscid fluid is investigated. The nonlinear equations of motion are studied by using a code based on arclength continuation method. A series of accurate experiments on forced vibrations of an empty and water-filled stainless-steel Shell have been performed. Several modes have been intensively investigated for different vibration amplitudes. A closed loop control of the force excitation has been used. The actual geometry of the test Shell has been measured and the geometric imperfections have been introduced in the theoretical model. Several interesting nonlinear phenomena have been experimentally observed and numerically reproduced, as: softening-type nonlinearity, different types of travelling wave response in the proximity of resonances and amplitude-modulated response. For all the modes investigated, the theoretical and experimental results are in strong agreement.Copyright © 2002 by ASME
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VIBRATIONS OF FLUID-FILLED HERMETIC CANS
Journal of Fluids and Structures, 2000Co-Authors: Marco AmabiliAbstract:Abstract Free, conservative vibrations of a hermetic can, Simply Supported at the base, are studied. The can is composed by a circular cylindrical Shell and two identical circular plates connected to the Shell at its ends. The artificial spring method, which is an extension of the classical Rayleigh–Ritz method, is used to solve the system by using substructuring. The can is studied empty and filled with an inviscid and incompressible fluid. Fluid volume conservation is applied. The interaction between the plates and the Shell via the fluid is considered, and exact expressions for the fluid velocity potential are used. The effect of flexibility of joints between plates and Shell is investigated. Results for a fluid-filled, Simply Supported Shell closed by rigid ends are also obtained and compared to the classical open-end Shell.
Tanish Dey - One of the best experts on this subject based on the ideXlab platform.
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Non-linear vibration response of functionally graded circular cylindrical Shells subjected to thermo-mechanical loading
Composite Structures, 2019Co-Authors: Amit Yadav, Marco Amabili, Sarat Kumar Panda, Tanish DeyAbstract:Abstract The analysis of the non-linear vibration response is carried out for functionally graded (FG) circular cylindrical Shells subjected to thermal environment along with mechanical in-plane non-uniformly distributed loading along the edges and harmonic radial force. The temperature dependent material properties of the Simply Supported Shell are assumed to vary in the radial direction according to power-law distribution. Based on the first-order shear deformation theory and von-Karman type geometric nonlinearity, the strain-displacement relationships are established for circular cylindrical Shells. The coupled governing equations of motion for functionally graded cylindrical Shells are then derived using Hamilton’s principle. Employing Galerkin’s method, the coupled partial differential equations of motions are reduced to a set of non-linear ordinary differential equations. In order to obtain the free and forced vibration response of the FG Shell, the incremental harmonic balance method, in conjunction with the arc-length method, is used. The non-uniform in-plane loading is converted to Fourier series and the pre-buckling analysis is performed to determine the stress distribution within the Shell. The non-linear frequency-amplitude response is studied to examine the effects of volume fractions of the constituents, static partial edge loadings, thermal loads, and radial periodic loadings.
Francesco Pellicano - One of the best experts on this subject based on the ideXlab platform.
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stability and vibration of empty and fluid filled circular cylindrical Shells under static and periodic axial loads
International Journal of Solids and Structures, 2003Co-Authors: Francesco Pellicano, Marco AmabiliAbstract:Abstract In the present study, the dynamic stability of Simply Supported, circular cylindrical Shells subjected to dynamic axial loads is analysed. Geometric nonlinearities due to finite-amplitude Shell motion are considered by using the Donnell’s nonlinear shallow-Shell theory. The effect of structural damping is taken into account. A discretization method based on a series expansion involving a relatively large number of linear modes, including axisymmetric and asymmetric modes, and on the Galerkin procedure is developed. Axisymmetric modes are included; indeed, they are essential in simulating the inward deflection of the mean oscillation with respect to the equilibrium position and in describing the axisymmetric deflection due to axial loads. A finite length, Simply Supported Shell is considered; the boundary conditions are satisfied, including the contribution of external axial loads acting at the Shell edges. The effect of a contained liquid is investigated. The linear dynamic stability and nonlinear response are analysed by using continuation techniques and direct simulations.
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Nonlinear dynamics and stability of compressed circular cylindrical Shells
Computational Fluid and Solid Mechanics 2003, 2003Co-Authors: Francesco Pellicano, Marco AmabiliAbstract:Publisher Summary In this chapter, the dynamic stability of Simply Supported, circular cylindrical Shells under periodic axial loads is analyzed. Nonlinearities because of finite-amplitude Shell motion are considered by using the Donnell's nonlinear shallow-Shell theory. A finite length, Simply Supported Shell is considered; the boundary conditions are satisfied, including the contribution of external axial loads acting at the Shell edges. The effect of a contained liquid on the dynamic stability is investigated. The Shell is either empty or completely fluidfilled. An incompressible inviscid fluid is considered and the effect of the dynamic pressure acting on the Shell surface is linearized in the process. The fluid velocity field is described in terms of the velocity potential Ф. To quantify the effect of a contained fluid and the damping, the dynamic critical loads are computed for different excitation frequencies, damping ratios and considering empty and water-filled Shells.
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Large-Amplitude Vibrations of Empty and Fluid-Filled Circular Cylindrical Shells With Imperfections: Theory and Experiments
5th International Symposium on Fluid Structure Interaction Aeroelasticity and Flow Induced Vibration and Noise, 2002Co-Authors: Marco Amabili, M. Pellegrini, Francesco PellicanoAbstract:The large-amplitude response of perfect and imperfect, Simply Supported circular cylindrical Shells to harmonic excitation in the spectral neighbourhood of some of the lowest natural frequencies is investigated. Donnell’s nonlinear shallow-Shell theory is used and the solution is obtained by Galerkin method. Several expansions involving 16 or more natural modes of the Shell are used. The boundary conditions on the radial displacement (Simply Supported Shell at both ends) and the continuity of circumferential displacement are exactly satisfied. The effect of internal quiescent, incompressible and inviscid fluid is investigated. The nonlinear equations of motion are studied by using a code based on arclength continuation method. A series of accurate experiments on forced vibrations of an empty and water-filled stainless-steel Shell have been performed. Several modes have been intensively investigated for different vibration amplitudes. A closed loop control of the force excitation has been used. The actual geometry of the test Shell has been measured and the geometric imperfections have been introduced in the theoretical model. Several interesting nonlinear phenomena have been experimentally observed and numerically reproduced, as: softening-type nonlinearity, different types of travelling wave response in the proximity of resonances and amplitude-modulated response. For all the modes investigated, the theoretical and experimental results are in strong agreement.Copyright © 2002 by ASME
Giorgio Dalpiaz - One of the best experts on this subject based on the ideXlab platform.
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Free Vibrations of Cylindrical Shells with Non-Axisymmetric Mass Distribution on Elastic Bed
Meccanica, 1997Co-Authors: Marco Amabili, Giorgio DalpiazAbstract:The free vibrations of circular cylindrical Shells partiallyloaded by a distributed mass and rested on an elastic bed are studied in this paper. Both the mass-load and the elastic bed are assumed to be applied on limited arcs and with arbitrary distributions in circumferential direction,while they are considered to be uniformly distributed in longitudinaldirection on the entire Shell length. Therefore, the problem is notaxisymmetric. The solution is obtained by using the development of theflexural mode shapes in a Fourier series, whose coefficients are determinedby rendering the Rayleigh quotient stationary, so a Galerkin equation isobtained. The proposed method is independent of the boundary conditionsat the Shell ends. The results are satisfactorily compared to FEM results.Finally, the influence of the mass-load and of the bed stiffness on thenatural frequencies and mode shapes of a Simply Supported Shell is shownand discussed.
Amit Yadav - One of the best experts on this subject based on the ideXlab platform.
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Non-linear vibration response of functionally graded circular cylindrical Shells subjected to thermo-mechanical loading
Composite Structures, 2019Co-Authors: Amit Yadav, Marco Amabili, Sarat Kumar Panda, Tanish DeyAbstract:Abstract The analysis of the non-linear vibration response is carried out for functionally graded (FG) circular cylindrical Shells subjected to thermal environment along with mechanical in-plane non-uniformly distributed loading along the edges and harmonic radial force. The temperature dependent material properties of the Simply Supported Shell are assumed to vary in the radial direction according to power-law distribution. Based on the first-order shear deformation theory and von-Karman type geometric nonlinearity, the strain-displacement relationships are established for circular cylindrical Shells. The coupled governing equations of motion for functionally graded cylindrical Shells are then derived using Hamilton’s principle. Employing Galerkin’s method, the coupled partial differential equations of motions are reduced to a set of non-linear ordinary differential equations. In order to obtain the free and forced vibration response of the FG Shell, the incremental harmonic balance method, in conjunction with the arc-length method, is used. The non-uniform in-plane loading is converted to Fourier series and the pre-buckling analysis is performed to determine the stress distribution within the Shell. The non-linear frequency-amplitude response is studied to examine the effects of volume fractions of the constituents, static partial edge loadings, thermal loads, and radial periodic loadings.