Free vibration and dynamic stability of functionally graded composite microtubes reinforced with graphene platelets

2021 ◽  
Vol 272 ◽  
pp. 114231
Author(s):  
Lu Lu ◽  
Shuang Wang ◽  
Min Li ◽  
Xingming Guo
Keyword(s):  
Free Vibration ◽  
Dynamic Stability ◽  
Functionally Graded ◽  
Functionally Graded Composite ◽  
Graphene Platelets

Analysis of vibration in rotating pretwisted functionally graded graphene platelets reinforced nanocomposite laminated blades with an attached point mass

2021 ◽  
pp. 095440622110084
Author(s):  
Amin Ghorbani Shenas ◽  
Parviz Malekzadeh ◽  
Sima Ziaee
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Polymer Matrix ◽  
Natural Frequencies ◽  
Weight Fraction ◽  
Functionally Graded ◽  
Point Mass ◽  
Attached Mass ◽  
Graphene Platelets ◽  
Twisted Beam

This work presents an investigation on the free vibration behavior of rotating pre-twisted functionally graded graphene platelets reinforced composite (FG-GPLRC) laminated blades/beams with an attached point mass. The considered beams are constituted of [Formula: see text] layers which are bonded perfectly and made of a mixture of isotropic polymer matrix and graphene platelets (GPLs). The weight fraction of GPLs changes in a layer-wise manner. The effective material properties of FG-GPLRC layers are computed by using the modified Halpin-Tsai model together with rule of mixture. The free vibration eigenvalue equations are developed based on the Reddy’s third-order shear deformation theory (TSDT) using the Chebyshev–Ritz method under different boundary conditions. After validating the approach, the influences of the GPLs distribution pattern, GPLs weight fraction, angular velocity, the variation of the angle of twist along the beam axis, the ratio of attached mass to the beam mass, boundary conditions, position of attached mass, and geometry on the vibration behavior are investigated. The findings demonstrate that the natural frequencies of the rotating pre-twisted FG-GPLRC laminated beams significantly increases by adding a very small amount of GPLs into polymer matrix. It is shown that placing more GPLs near the top and bottom surfaces of the pre-twisted beam is an effective way to strengthen the pre-twisted beam stiffness and increase the natural frequencies.

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.

Free Vibration Analysis of Multilayered Functionally Graded Composite Cylinder

2010 ◽  
Author(s):  
M. H. Kargarnovin ◽  
M. Hashemi
Keyword(s):  
Free Vibration ◽  
Volume Fraction ◽  
Equations Of Motion ◽  
Free Vibration Analysis ◽  
Longitudinal Direction ◽  
Element Model ◽  
Functionally Graded ◽  
Composite Cylinder ◽  
Shape Functions ◽  
Functionally Graded Composite

Free vibration of multilayered composite cylinder which volume fraction of fiber varies according to power law in longitudinal direction has been studied. Rule of mixture model and reverse of that are employed to represent elastic properties of this fibrous functionally graded composite. Strain-displacement relations employed are based on Reissner-Naghdi-Berry’s shell theory. The displacement finite element model of the governing equations of motion is derived by writing weak form of them. The Lagrangian shape functions for in-plane displacements and Hermitian shape functions for displacement in normal direction to the surface of mid-plane are utilized by defining a conformal quadrilateral element. The results show that by appropriate grading material properties of fiber in longitudinal direction the natural frequencies can be increased in comparison with traditional composite in which volume fraction of fiber does not vary.

Free vibration behavior of corrugated functionally graded composite panel

2020 ◽  
Vol 22 ◽  
pp. 2957-2963
Author(s):  
Abhilash Karakoti ◽  
Satyasreet Jena ◽  
Vishesh Ranjan Kar ◽  
Kandasamy Jayakrishna
Keyword(s):  
Free Vibration ◽  
Functionally Graded ◽  
Composite Panel ◽  
Functionally Graded Composite ◽  
Vibration Behavior
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