Vibrational characteristics of a higher-order laminated composite viscoelastic annular microplate via modified couple stress theory

In this article, amplitude, and vibrational characteristics of a rotating laminated cantilever microdisk are presented. The centrifugal and Coriolis effects due to the rotation are considered. The strain and stress relations can be determined via the higher-order shear deformable theory (HSDT). For accessing to size-effects, the nonlocal strain gradient theory (NSGT) is used for obtaining the correct results. The boundary conditions are derived through governing equations of the laminated rotating microdisk using an energy method known as Hamilton's principle and finally are solved using generalized differential quadrature method (GDQM). Vibration characteristics of the spinning microdisk with various boundary conditions are described based on the curves drawn by Matlab software. Also, the simply-supported conditions are applied to edges θ = π / 2 , and θ = 3 π / 2 , and, cantilever (clamped–free) boundary conditions are investigated in R = Ri, and R0, respectively. Apart from the numerical solution, a 3-D finite element model using ABAQUS software is presented using the finite element package to simulate the response of the laminated cantilever disk. The results created from a finite element simulation illustrates a close agreement with the semi-numerical method results. The outcomes show that the number of layers, angle of ply, angular velocity speed, length scale, and nonlocal parameters, and geometrically properties of microdisk have a considerable impact on the amplitude, and vibration behavior of a rotating laminated cantilever microdisk. As an applicable result in related industries, if the structure is made of an even number of layers, the frequency response of the system would be better, especially at the smaller values of the radius ratio.

Frequency and critical angular velocity characteristics of rotary laminated cantilever microdisk via two-dimensional analysis

In this study, the flutter analysis of a rotating pre-twisted functionally graded graphene nanoplatelets reinforced composite (FG GPLRC) blade under supersonic airflow is investigated. The pre-twisted blade is multi-layered and reinforced with graphene nanoplatelets (GPLs) evenly distributed in each layer while the GPL weight fraction changes from layer to layer through the thickness direction. The effective Young's modulus is determined by Halpin-Tsai micromechanical model while the Poisson's ratio and mass density are predicted by Voigt's rule for GPLRC layers. According to assumptions of the first-order shear deformation theory (FSDT), the first-order piston theory and shell theory, the dynamic model of rotating pre-twisted GPLRC blades subjected to supersonic flow is developed. Meshless the improved moving least-square Ritz method (IMLS-Ritz) is used to derive the discrete dynamic equations of rotating pre-twisted GPLRC blades under aerodynamic load. The accuracy of the IMLS-Ritz method for this problem is validated by comprehensive convergence studies and careful comparison studies. A detailed parameter investigation of the effects of GPL distribution configuration, rotation velocity and geometrical parameters on flutter behavior characteristics of GPLRC blades is systematically conducted.

Meshless numerical approach to flutter analysis of rotating pre-twisted nanocomposite blades subjected to supersonic airflow

Predicting vibration characteristics of rotating composite blades containing CNT-reinforced composite laminae and damaged fiber-reinforced composite laminae

The primary resonance and nonlinear vibrations of the functionally graded graphene platelet (FGGP)-reinforced rotating pretwisted composite blade under combined the external and multiple parametric excitations are investigated with three different distribution patterns The FGGP-reinforced rotating pretwisted composite blade is simplified to the rotating pretwisted composite cantilever plate reinforced by the functionally graded graphene platelet It is novel to simplify the leakage of the airflow in the tip clearance to the non-uniform axial excitation The rotating speed of the steady state adding a small periodic perturbation is considered The aerodynamic load subjecting to the surface of the plate is simulated as the transverse excitation Utilizing the first-order shear deformation theory, von Karman nonlinear geometric relationship, Lagrange equation and mode functions satisfying the boundary conditions, three-degree-of-freedom nonlinear ordinary differential equations of motion are derived for the FGGP-reinforced rotating pretwisted composite cantilever plate under combined the external and multiple parametric excitations The primary resonance and nonlinear dynamic behaviors of the FGGP-reinforced rotating pretwisted composite cantilever plate are analyzed by Runge–Kutta method The amplitude–frequency response curves, force–frequency response curves, bifurcation diagrams, maximum Lyapunov exponent, phase portraits, waveforms and Poincare map are obtained to investigate the nonlinear dynamic responses of the FGGP-reinforced rotating pretwisted composite cantilever plate under combined the external and multiple parametric excitations

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Nonlinear Vibrations of Rotating Pretwisted Composite Blade Reinforced by Functionally Graded Graphene Platelets Under Combined Aerodynamic Load and Air Flow in Tip Clearance

Rengjin Xiang

Papers

A study of the vibration and lay-up optimization of rotating cross-ply laminated nanocomposite blades