Guided waves propagation in sandwich cylindrical structures with functionally graded graphene-epoxy core and piezoelectric surface layers

2020 ◽  
pp. 109963622095903
Author(s):  
Chunlei Li ◽  
Qiang Han
Keyword(s):  
Wave Propagation ◽  
Isogeometric Analysis ◽  
Sandwich Structure ◽  
Guided Waves ◽  
Distribution Patterns ◽  
Spectral Element ◽  
Functionally Graded ◽  
Surface Layers ◽  
Cylindrical Structure ◽  
Graphene Platelets

As an ideal reinforcing nanofiller, graphene platelets (GPLs) can significantly improve physical properties of nanocomposites, which have attracted considerable attention for design and development of advanced lightweight nanocomposite structures in engineering. In this paper, a sandwich cylindrical structure is considered for dispersion properties of wave propagation by axisymmetric isogeometric analysis (IGA). The sandwich structure is composed of a functionally graded (FG) nanocomposite core and piezoelectric surface layers. Graphene platelets are dispersed in the interlayer by three typical distribution patterns through the thickness. In virtue of the symmetry and the advantages of isogeometric analysis, the sandwich cylindrical structure can be described by one-dimensional representation along the radial direction. Based on Hamilton’s principle, parameterized governing equation for wave propagation is obtained with the non-uniform rational B-splines (NURBS), which leads to an second-order eigenvalue problem. The modified wave finite element (WFE) method and the Chebyshev spectral element (SE) method are utilized to verify the reliability and accuracy of this approach. Then, the effects of several significant parameters of GPLs and geometric sizes of the sandwich structure on wave propagation characteristics are discussed in details. The results of this study are beneficial to deeply understanding and control of wave propagation in advanced piezoelectric composites for the applications in structural health monitoring and nondestructive evaluation.

scholarly journals Elasticity Solutions for In-Plane Free Vibration of FG-GPLRC Circular Arches with Various End Conditions

2020 ◽  
Vol 10 (14) ◽  
pp. 4695
Author(s):  
Dongying Liu ◽  
Jing Sun ◽  
Linhua Lan
Keyword(s):  
Free Vibration ◽  
Weight Fraction ◽  
Distribution Patterns ◽  
Theory Of Elasticity ◽  
Functionally Graded ◽  
Scaled Model ◽  
Circular Arch ◽  
End Conditions ◽  
Elasticity Solutions ◽  
Graphene Platelets

In-plane free vibration of functionally graded graphene platelets reinforced nanocomposites (FG-GPLRCs) circular arches is investigated by using the two-dimensional theory of elasticity. The graphene platelets (GPLs) are dispersed along the thickness direction non-uniformly, and the material properties of the nanocomposites are evaluated by the modified Halpin-Tsai multi-scaled model and the rule of mixtures. A state-space method combined with differential quadrature technique is employed to derive the governing equation for in-plane free vibration of FG-GPLRCs circular arch, the semi-analytical solutions are obtained for various end conditions. An exact solution of FG-GPLRCs circular arch with simply-supported ends is also presented as a benchmark to valid the present numerical method. Numerical examples are performed to study the effects of GPL distribution patterns, weight fraction and dimensions, geometric parameters and boundary conditions of the circular arch on the natural frequency in details.

Three-dimensional static and free vibration analysis of graphene platelet–reinforced porous composite cylindrical shell

2020 ◽  
Vol 26 (19-20) ◽  
pp. 1627-1645 ◽  
Author(s):  
Alireza Rahimi ◽  
Akbar Alibeigloo ◽  
Mehran Safarpour
Keyword(s):  
Cylindrical Shell ◽  
Free Vibration ◽  
Boundary Conditions ◽  
Distribution Patterns ◽  
Functionally Graded ◽  
Fourier Series Expansion ◽  
Graphene Platelet ◽  
Vibration Behavior ◽  
Reinforced Composite ◽  
Graphene Platelets

Because of promoted thermomechanical performance of functionally graded graphene platelet–reinforced composite ultralight porous structural components, this article investigates bending and free vibration behavior of functionally graded graphene platelet–reinforced composite porous cylindrical shell based on the theory of elasticity. Effective elasticity modulus of the composite is estimated with the aid of modified version of Halpin–Tsai micromechanics. Rule of mixtures is used to obtain mass density and Poisson’s ratio of the graphene platelet–reinforced composite shell. An analytical solution is introduced to obtain the natural frequencies and static behavior of simply supported cylindrical shell by applying the state-space technique along the radial coordinate and Fourier series expansion along the circumferential and axial direction. In addition, differential quadrature method is used to explore the response of the cylindrical shell in the other cases of boundary conditions. Validity of the applied approach is examined by comparing the numerical results with those published in the available literature. A comprehensive parametric study is conducted on the effects of different combinations of graphene platelets distribution patterns and porosity distribution patterns, boundary conditions, graphene platelets weight fraction, porosity coefficient, and geometry of the shell (such as mid-radius to thickness ratio and length to mid-radius ratio) on the bending and free vibration behavior of the functionally graded graphene platelet–reinforced composite porous cylindrical shell. The results of this study provide useful practical tips for engineers designing composite structures.

Isogeometric Analysis of Functionally-Graded Graphene Platelets Reinforced Porous Nanocomposite Plates Using a Refined Plate Theory

2020 ◽  
Vol 20 (07) ◽  
pp. 2050076
Author(s):  
Duc-Huynh Phan
Keyword(s):  
Forced Vibration ◽  
Isogeometric Analysis ◽  
Plate Theory ◽  
Mass Density ◽  
Weight Fraction ◽  
Functionally Graded ◽  
Integration Scheme ◽  
Dispersion Pattern ◽  
Refined Plate Theory ◽  
Graphene Platelets

In this study, we propose a novel and effective computational approach for free and forced vibration analyses of functionally graded (FG) porous plates with graphene platelets (GPLs) reinforcement under various loads. To this end, the outstanding features of isogeometric analysis (IGA) are first combined with the four-variable refined plate theory (RPT). The non-uniform rational B-splines (NURBS) are adopted to obtain the [Formula: see text]-continuity essential to the RPT model. The various distributions of internal pores as well as GPLs with uniform or non-uniform properties along the plate’s thickness are investigated. The effective elastic properties of the material models are obtained by the Halpin–Tsai micromechanics model for Young’s modulus, the rule of mixture for Poisson’s ratio and mass density. The Newmark’s time integration scheme is implemented to obtain the solutions of the forced vibration problems. Numerical examples are carried out to investigate the effects of various key parameters such as porosity coefficient, GPL weight fraction, porosity distribution, as well as GPL dispersion pattern, on the behaviors of the plate structure.

Evaluation of Adhesive Interface Properties in Honeycomb Sandwich Structure Using Guided Waves

2021 ◽  
Author(s):  
Parambeer Singh Negi ◽  
Dileep Koodalil ◽  
Krishnan Balasubramaniam
Keyword(s):  
Wave Propagation ◽  
Sandwich Structure ◽  
Guided Waves ◽  
Wave Mode ◽  
Guided Wave ◽  
Sh Wave ◽  
Bond Quality ◽  
Honeycomb Sandwich ◽  
Oriented Parallel ◽  
Honeycomb Sandwich Structure

Abstract A method is presented to evaluate the interfacial weakness of aluminium-based honeycomb sandwich structure (HSS) using Shear Horizontal (SH) guided wave. SH guided waves are sensitive to the interfacial properties since the wave particles vibration is oriented parallel to the adhesive-adherent joints. Periodic permanent magnet (PPM) electromagnetic acoustic transducers (EMATs) are used to excite and detect SH-guided waves. A semi-analytical finite element method is developed to simulate the SH wave propagation in HSS. The boundary stiffness approach is used to model the adhesive-adherent interface. The excitation parameters are chosen such that only SH0 mode is generated in the structure. The interaction of the fundamental SH0 wave mode with various defects and the different interface stiffness is analyzed. The frequency-wavenumber analysis is used to study the effect of interface stiffness on SH wave propagation. The analysis reveals that in a perfect bond, SH0 and S0 guided modes are present. The interaction of SH0 mode with the honeycomb core results in the genesis of S0 mode. Thus, the presence or absence of the S0 mode can be used as an indicator of bond quality. The findings from the FE simulation are validated against the experiment. The analysis shows a reliable non-destructive evaluation of the interface joint and classifying them as good or bad bonds.

scholarly journals Theoretical and Numerical Solution for the Bending and Frequency Response of Graphene Reinforced Nanocomposite Rectangular Plates

2021 ◽  
Vol 11 (14) ◽  
pp. 6331
Author(s):  
Mehran Safarpour ◽  
Ali Forooghi ◽  
Rossana Dimitri ◽  
Francesco Tornabene
Keyword(s):  
Boundary Conditions ◽  
Thermal Conditions ◽  
Distribution Patterns ◽  
Functionally Graded ◽  
Rectangular Plates ◽  
Total Potential ◽  
Reinforced Composite ◽  
Graphene Platelets ◽  
Generalized Differential ◽  
Minimum Total Potential Energy

In this work, we study the vibration and bending response of functionally graded graphene platelets reinforced composite (FG-GPLRC) rectangular plates embedded on different substrates and thermal conditions. The governing equations of the problem along with boundary conditions are determined by employing the minimum total potential energy and Hamilton’s principle, within a higher-order shear deformation theoretical setting. The problem is solved both theoretically and numerically by means of a Navier-type exact solution and a generalized differential quadrature (GDQ) method, respectively, whose results are successfully validated against the finite element predictions performed in the commercial COMSOL code, and similar outcomes available in the literature. A large parametric study is developed to check for the sensitivity of the response to different foundation properties, graphene platelets (GPL) distribution patterns, volume fractions of the reinforcing phase, as well as the surrounding environment and boundary conditions, with very interesting insights from a scientific and design standpoint.

A Benchmark Study of Modeling Lamb Wave Scattering by a Through Hole Using a Time-Domain Spectral Element Method

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Menglong Liu ◽  
David Schmicker ◽  
Zhongqing Su ◽  
Fangsen Cui
Keyword(s):  
Numerical Simulation ◽  
Wave Propagation ◽  
Time Domain ◽  
Lamb Wave ◽  
Spectral Element Method ◽  
Guided Waves ◽  
Three Dimensional ◽  
Spectral Element ◽  
Benchmark Study ◽  
Through Hole

Ultrasonic guided waves (GWs) are being extensively investigated and applied to nondestructive evaluation and structural health monitoring. Guided waves are, under most circumstances, excited in a frequency range up to several hundred kilohertz or megahertz for detecting defect/damage effectively. In this regard, numerical simulation using finite element analysis (FEA) offers a powerful tool to study the interaction between wave and defect/damage. Nevertheless, the simulation, based on linear/quadratic interpolation, may be inaccurate to depict the complex wave mode shape. Moreover, the mass lumping technique used in FEA for diagonalizing mass matrix in the explicit time integration may also undermine the calculation accuracy. In recognition of this, a time domain spectral element method (SEM)—a high-order FEA with Gauss–Lobatto–Legendre (GLL) node distribution and Lobatto quadrature algorithm—is studied to accurately model wave propagation. To start with, a simplified two-dimensional (2D) plane strain model of Lamb wave propagation is developed using SEM. The group velocity of the fundamental antisymmetric mode (A0) is extracted as indicator of accuracy, where SEM exhibits a trend of quick convergence rate and high calculation accuracy (0.03% error). A benchmark study of calculation accuracy and efficiency using SEM is accomplished. To further extend SEM-based simulation to interpret wave propagation in structures of complex geometry, a three-dimensional (3D) SEM model with arbitrary in-plane geometry is developed. Three-dimensional numerical simulation is conducted in which the scattering of A0 mode by a through hole is interrogated, showing a good match with experimental and analytical results.

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