scholarly journals Multiple Equilibria and Buckling of Functionally Graded Graphene Nanoplatelet-Reinforced Composite Arches with Pinned-Fixed End

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1003
Author(s):  
Zhicheng Yang ◽  
Jiamian Xu ◽  
Hanwen Lu ◽  
Jiangen Lv ◽  
Airong Liu ◽  
...  
Keyword(s):  
Multiple Equilibria ◽  
Virtual Work ◽  
Weight Fraction ◽  
Point Load ◽  
Functionally Graded ◽  
Buckling Load ◽  
Equilibrium Path ◽  
Graphene Nanoplatelet ◽  
Reinforced Composite ◽  
Non Linear

This paper presents an analytical study on the multiple equilibria and buckling of pinned-fixed functionally graded graphene nanoplatelet-reinforced composite (FG-GPLRC) arches under central point load. It is assumed that graphene nanoplatelets (GPLs) in each GPLRC layer are uniformly distributed and randomly oriented with its concentration varying layer-wise along the thickness direction. The Halpin–Tsai micromechanics-based model is used to estimate the effective elastic modulus of GPLRC. The non-linear equilibrium path and buckling load of the pinned-fixed FG-GPLRC arch are subsequently derived by employing the principle of virtual work. The effects of GPLs distribution, weight fraction, size and geometry on the buckling load are examined comprehensively. It is found that the buckling performances of FG-GPLRC arches can be significantly improved by using GPLs as reinforcing nanofillers. It is also found that the non-linear equilibrium path of the pinned-fixed FG-GPLRC arch have multiple limit points and non-linear equilibrium branches when the arch is with a special geometric parameter.

scholarly journals Vibration and Buckling Characteristics of Functionally Graded Graphene Nanoplatelets Reinforced Composite Beams with Open Edge Cracks

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1412 ◽  
Author(s):  
Meifung Tam ◽  
Zhicheng Yang ◽  
Shaoyu Zhao ◽  
Jie Yang
Keyword(s):  
Fundamental Frequency ◽  
Slenderness Ratio ◽  
Weight Fraction ◽  
Graphene Nanoplatelets ◽  
Functionally Graded ◽  
Buckling Load ◽  
Critical Buckling Load ◽  
Reinforced Composite ◽  
Edge Cracks ◽  
Open Edge

This paper investigates the free vibration and compressive buckling characteristics of functionally graded graphene nanoplatelets reinforced composite (FG-GPLRC) beams containing open edge cracks by using the finite element method. The beam is a multilayer structure where the weight fraction of graphene nanoplatelets (GPLs) remains constant in each layer but varies along the thickness direction. The effective Young’s modulus of each GPLRC layer is determined by the modified Halpin-Tsai micromechanics model while its Poisson’s ratio and mass density are predicted according to the rule of mixture. The effects of GPLs distribution pattern, weight fraction, geometry, crack depth ratio (CDR), slenderness ratio as well as boundary conditions on the fundamental frequency and critical buckling load of the FG-GPLRC beam are studied in detail. It was found that distributing more GPLs on the top and bottom surfaces of the cracked FG-GPLRC beam provides the best reinforcing effect for improved vibrational and buckling performance. The fundamental frequency and critical buckling load are also considerably affected by the geometry and dimension of GPL nanofillers.

scholarly journals Analytical Prediction for Nonlinear Buckling of Elastically Supported FG-GPLRC Arches under a Central Point Load

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2026
Author(s):  
Zhicheng Yang ◽  
Airong Liu ◽  
Jie Yang ◽  
Siu-Kai Lai ◽  
Jiangen Lv ◽  
...  
Keyword(s):  
Virtual Work ◽  
Micromechanical Model ◽  
Point Load ◽  
Functionally Graded ◽  
Central Point ◽  
Mode Switching ◽  
Equilibrium Path ◽  
Analytical Prediction ◽  
Nonlinear Buckling ◽  
Elastically Supported

In this paper, we present an analytical prediction for nonlinear buckling of elastically supported functionally graded graphene platelet reinforced composite (FG-GPLRC) arches with asymmetrically distributed graphene platelets (GPLs). The effective material properties of the FG-GPLRC arch are formulated by the modified Halpin–Tsai micromechanical model. By using the principle of virtual work, analytical solutions are derived for the limit point buckling and bifurcation buckling of the FG-GPLRC arch subjected to a central point load (CPL). Subsequently, the buckling mode switching phenomenon of the FG-GPLRC arch is presented and discussed. We found that the buckling modes of the FG-GPLRC arch are governed by the GPL distribution pattern, rotational restraint stiffness, and arch geometry. In addition, the number of limit points in the nonlinear equilibrium path of the FG-GPLRC arch under a CPL can be determined according to the bounds of successive inflexion points. The effects of GPL distribution patterns, weight fractions, and geometric configurations on the nonlinear buckling behavior of elastically supported FG-GPLRC arches are also comprehensively discussed.

scholarly journals Effect of Thickness Stretching on Bending and Free Vibration Behaviors of Functionally Graded Graphene Reinforced Composite Plates

2021 ◽  
Vol 11 (23) ◽  
pp. 11362
Author(s):  
Zhuangzhuang Wang ◽  
Liansheng Ma
Keyword(s):  
Free Vibration ◽  
Solution Method ◽  
Composite Plates ◽  
Weight Fraction ◽  
Functionally Graded ◽  
Navier Solution ◽  
Reinforced Composite ◽  
Number Of Layers ◽  
Asymmetrically Distributed ◽  
Stretching Effect

The focus of this paper is the effect of thickness stretching on the static and dynamic behaviors of functionally graded graphene reinforced composite (FG-GRC) plates. The bending and free vibration behaviors of FG-GRC plates under simply supported conditions are studied based on two plate theories, with or without taking into account the thickness stretching effect, respectively, and the effect of thickness stretching on FG-GRC plates is analyzed by comparing the calculated results of the two types of plate theories. The properties of composite materials are estimated by the modified Halpin-Tsai model and rule of mixture, Hamilton’s principle is used to construct its governing equation, and the Navier solution method is used to find the closed solution. The numerical results show that the effect of thickness stretching depends mainly on the transverse anisotropy of the FG-GRC plates, and the FG-GRC plates are most significantly affected by the thickness stretching when the graphene nanoplatelets (GPLs) are asymmetrically distributed, and the effect of thickness stretching tends to increase as the total number of layers and the weight fraction of GPLs increase.

Nonlinear dynamics of functionally graded graphene nanoplatelet reinforced polymer doubly-curved shallow shells resting on elastic foundation using a micromechanical model

2020 ◽  
pp. 109963622092665 ◽  
Author(s):  
Vu Ngoc Viet Hoang ◽  
Nguyen Duc Tien ◽  
Dinh Gia Ninh ◽  
Vu Toan Thang ◽  
Do Van Truong
Keyword(s):  
Nonlinear Vibration ◽  
Mathematical Formulation ◽  
Micromechanical Model ◽  
Graphene Nanoplatelets ◽  
Functionally Graded ◽  
Amplitude Curve ◽  
Graphene Nanoplatelet ◽  
Shallow Shells ◽  
Reinforced Composite ◽  
Doubly Curved

The paper focuses on the nonlinear vibration of functionally graded graphene nanoplatelet reinforced composite doubly curved shallow shells resting on elastic foundations. The graphene nanoplatelet reinforced composites are assumed to be distributed uniformly and functionally graded through the thickness. The material properties are assumed to be temperature-dependent and are estimated through the Halpin–Tsai micromechanical model, while the Poisson’s ratio, density mass, and thermal expansion are implemented by the rule of mixtures. The mathematical formulation is developed based on the classical shell theory and Von Karman-Donnell geometrical nonlinearity assumption. The dynamical responses of a simply supported functionally graded-graphene nanoplatelet reinforced composite doubly curved shallow shells are obtained by employing the Airy’s stress function and the Galerkin’s method. The responses of nonlinear vibration as time history, frequency-amplitude curve, phase plane graphs, and Poincare maps are carried out in this paper. In addition, the effects of the environment, graphene nanoplatelets weight fraction, graphene nanoplatelets distribution patterns, and thickness-to-length ratio are scrutinized. The obtained results are also compared and validated with those of other studies.

scholarly journals Nonlinear Buckling of Fixed Functionally Graded Material Arches Under a Locally Uniformly Distributed Radial Load

2021 ◽  
Vol 8 ◽  
Author(s):  
Hanwen Lu ◽  
Jinman Zhou ◽  
Zhicheng Yang ◽  
Airong Liu ◽  
Jian Zhu
Keyword(s):  
Limit Point ◽  
Functionally Graded ◽  
Buckling Load ◽  
Equilibrium Path ◽  
Radial Load ◽  
Buckling Loads ◽  
Buckling Behavior ◽  
Bifurcation Buckling ◽  
Nonlinear Equilibrium ◽  
Graded Material

Functionally graded material (FGM) arches may be subjected to a locally radial load and have different material distributions leading to different nonlinear in-plane buckling behavior. Little studies is presented about effects of the type of material distributions on the nonlinear in-plane buckling of FGM arches under a locally radial load in the literature insofar. This paper focuses on investigating the nonlinear in-plane buckling behavior of fixed FGM arches under a locally uniformly distributed radial load and incorporating effects of the type of material distributions. New theoretical solutions for the limit point buckling load and bifurcation buckling loads and nonlinear equilibrium path of the fixed FGM arches under a locally uniformly distributed radial load that are subjected to three different types of material distributions are derived. The comparisons between theoretical and ANSYS results indicate that the theoretical solutions are accurate. In addition, the critical modified geometric slendernesses of FGM arches related to the switches of buckling modes are also derived. It is found that the type of material distributions of the fixed FGM arches affects the limit point buckling loads and bifurcation buckling loads as well as the nonlinear equilibrium path significantly. It is also found that the limit point buckling load and bifurcation buckling load increase with an increase of the modified geometric slenderness, the localized parameter and the proportional coefficient of homogeneous ceramic layer as well as a decrease of the power-law index p of material distributions of the FGM arches.

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