Nonlocal vibration characteristics of a functionally graded porous cylindrical nanoshell integrated with arbitrary arrays of piezoelectric elements

Heidari, Yaser; Arefi, Mohammad; Rahaghi, Mohsen Irani

doi:10.1080/15397734.2020.1830799

Cited by 20 publications

(4 citation statements)

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“…Due to the recent technological development in engineering practice, the characteristic size of structures become smaller and smaller [33][34][35][36], including the micro beam [37][38][39] with Winkler elastic foundation [40], micro torus plate [41], micro cylindrical shell [42,43], micro-structure on elastic foundation [44], and fluidconveying micro pipe [45]. The study of micro-scale pipes is an important research direction of the dynamics of fluid-conveying pipes.…”

Section: Introductionmentioning

confidence: 99%

Periodic motion of macro- and/or micro-scale cantilevered fluid-conveying pipes with O(2) symmetry: a finite dimensional analysis

Guo

2024

Front. Phys.

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Introduction: In this study, the spatial bending vibration of macro- and/or micro-scale cantilevered fluid-conveying pipes is investigated through finite dimensional analysis.Methods: Firstly, the Galerkin method is employed to discretize the partial differential equations of motion of the system into a system of ordinary differential equations. Then, the projection method based on center manifold-normal form theory is adopted to derive the coefficient formula that determines the pipe’s nonlinear dynamic behaviors, i.e., the change rate of the real part of the critical eigenvalue with respect to the flow velocity and the nonlinear resonance term, thereby obtaining reduced-order equations. Compared to previous studies that relied on the numerical solution of ordinary differential equations to determine the existence and stability of periodic motion, this paper concludes the existence and stability of periodic motion by utilizing the coefficients of the Galerkin discretized equations and the reduced-order equations, significantly saving time in determining the dynamic properties of pipes.Results and discussion: Subsequently, by investigating the reduced-order equations under specific parameters, the existence and stability of the two types of periodic motion of the pipe are studied. For macro pipes, the truncated mode numbers are set incrementally to calculate the coefficients of the reduced-order equations, investigate the distribution of the stability of the two types of periodic motions with the mass ratio, and carry out a longitudinal comparison (i.e., the comparison between the results obtained under different truncated mode numbers) as well as a horizontal comparison (i.e., the comparison of results between the finite dimensional analysis and the infinite dimensional analysis). It is found that the reasonable truncated mode number required to study this type of system is 15. Previous studies primarily focused on the convergence of frequency and amplitude when determining the truncated mode numbers. On this basis, our study further examines the convergence of motion forms with respect to the truncated mode numbers. Finally, based on the Galerkin discretization equations of 15 modes, the distribution of the stability of two types of the periodic motion of micro pipes with the mass ratio is analyzed. For macro- and micro-scale pipes, when the truncated mode number is 15, the error between the finite dimensional analysis results and the infinite dimensional analysis results is calculated to be about 7%. The above results are verified by obtaining the numerical solution to Galerkin discretization equations.

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Section: Introductionmentioning

confidence: 99%

Periodic motion of macro- and/or micro-scale cantilevered fluid-conveying pipes with O(2) symmetry: a finite dimensional analysis

Guo

2024

Front. Phys.

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“…It is found that the presence of cracks weakened oil film forces of the bearing-rotor system at high speeds, the clearance ratio had a greater effect on internal and external oil film vorticity, and the rotor operating stability can be improved by increasing the impeller eccentricity. Irani-Rahaghi et al 42 and Heidari et al [43][44][45][46] studied free vibration of functionally sandwich cylindrical shells integrated with a piezoelectric layer.…”

Section: Introductionmentioning

confidence: 99%

Vibration characteristics of turbocharger rotor system considering internal thread texture parameters of semi-floating ring bearing

Zhong

Jiang

Bin

et al. 2023

Proceedings of the Institution of Mechanical Engineers, Part J:

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The internal thread texture causes changes in the dynamic characteristics of the oil film of the semi-floating ring bearing, which affects the amplitude of vibration and operating life of the turbocharger rotor system. Based on the fluid lubrication theory, the oil film governing equation of a semi-floating ring bearing with surface texture parameters is derived. The effects of the texture depth, position, and number of turns of the internal thread on the dynamic characteristics of the bearing oil film, such as the maximum pressure, load-carrying capacity and stiffness damping, are analyzed. Taking a type of turbocharger as an example, a hydrodynamic model is established to analyze the oil film lubrication in the semi-floating ring bearings, and the dynamic characteristic of the oil film is analyzed by computational fluid dynamics method. The results show that the maximum pressure, bearing capacity, and stiffness damping coefficient of oil film increase firstly and then decrease with the increase of texture depth and the number of thread turns in the range of journal rotation speed from 1000 to 20,0000 r/min. Compared with the non-texture bearings, the dynamic characteristics coefficients of the oil film such as bearing capacity and stiffness damping increase the most, when the depth of texture is 0.006 mm and the number of thread turns is 9. Secondly, the dynamic characteristic coefficient of oil film is improved when the texture is distributed in the middle than on both sides. The thread texture with appropriate parameters can suppress the rotor system vibration amplitude. The conclusion can provide a reference for the design of textual parameters of semi-floating ring bearings.

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“…Zhang [25] examined the behavior of damping and free vibration for sandwich plates made of porous functionally graded materials corresponding to the modified Fourier-Ritz method. Heidari et al [26] proposed an analytical method for studying the conduct of free vibration in small-scale circular cylindrical shells made of uniformly graded material and surrounded on both sides by a piezoelectric array. Akbaş et al [27] investigated dynamic responses of a thick beam rested on the two viscoelastic supports formed of porous functionally graded layers under sine pulse load.…”

Section: Introductionmentioning

confidence: 99%

Frequency of Non-Linear Dynamic Response of a Porous Functionally Graded Cylindrical Panels

Mouthanna

Bakhy²,

Al-Waily³

2022

Jurnal Teknologi

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In this article, a nonlinear dynamical investigation of porose functionally graded cylindrical panels using a proposed analytical model is carried out. The material's properties are considered to be porosity-dependent and graded in the thickness direction, corresponding to a power-law distribution. The classical shell theory, with the geometrical shape of nonlinear in von Karman–Donnell, is employed to get the Lagrange motion equations. By applying the Galerkin procedure, the system of nonlinear dynamic vibration equations is found. The natural frequencies and dynamic amplitude vibrations are obtained by using the fourth-order Runge–Kutta approach. In numerical analyses, the effects of porosity factor, power-law index, porous FGM thickness, frequency–amplitude relation, and excitation force on the dynamic response of thin functionally graded porous cylindrical panels are investigated. Through the obtained results, it is discovered that the porosity coefficients have important effects on the natural frequencies and amplitude of the nonlinear dynamic response of the FG structures. It leads to a reduction in natural frequencies by 5.74 % at 10% pores.

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Nonlocal vibration characteristics of a functionally graded porous cylindrical nanoshell integrated with arbitrary arrays of piezoelectric elements

Cited by 20 publications

References 50 publications

Periodic motion of macro- and/or micro-scale cantilevered fluid-conveying pipes with O(2) symmetry: a finite dimensional analysis

Periodic motion of macro- and/or micro-scale cantilevered fluid-conveying pipes with O(2) symmetry: a finite dimensional analysis

Vibration characteristics of turbocharger rotor system considering internal thread texture parameters of semi-floating ring bearing

Frequency of Non-Linear Dynamic Response of a Porous Functionally Graded Cylindrical Panels

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