Panel flutter of curvilinear composite laminated plates in the presence of delamination

2018 ◽  
Vol 52 (20) ◽  
pp. 2789-2801 ◽  
Author(s):  
Jamshid Fazilati
Keyword(s):  
Fiber Orientation ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Axial Direction ◽  
Laminated Plates ◽  
Fiber Placement ◽  
Aerodynamic Pressure ◽  
Finite Strip Method ◽  
Loading Effects ◽  
Stiffness Characteristics

The effect of variable fiber placement angle on the supersonic linear flutter of rectangular composite panels containing square delamination zone is investigated using an enhanced spline version of finite strip method (FSM). The location dependent stiffness characteristics and mass matrices due to variable fiber orientation angles within every ply are extracted. The structural formulation is based on the higher-order shear deformation theory while the first-order piston theory is utilized to predict the loading effects of the supersonic airflow. Laminated composite material with varying fiber orientation angles along the axial direction is considered. The effect of aerodynamic damping is overlooked. The flutter coalescence of vibration modes is then traced using a standard eigenvalue procedure. Some representative results are provided to show the accuracy and capability of the developed formulation. The effects of material layup as well as geometry on the flutter behavior of laminated panels are then studied and the variation of critical aerodynamic pressure considering different delamination size, delamination depth, and boundary conditions are examined.

A Semi-Energy Finite Strip Method for Post-Buckling Analysis of Relatively Thick Anti-Symmetric Cross-Ply Laminates

2011 ◽  
Vol 471-472 ◽  
pp. 426-431 ◽  
Author(s):  
Mohammad Hajikazemi ◽  
Hamid Reza Ovesy ◽  
Mohammad Homayoun Sadr-Lahidjani
Keyword(s):  
Closed Form Solution ◽  
Shear Deformation Theory ◽  
Composite Plates ◽  
Form Solution ◽  
Laminated Plates ◽  
Plane Boundary ◽  
Finite Strip ◽  
Strip Method ◽  
Finite Strip Method ◽  
Post Buckling

In the current paper, a new semi-energy finite strip method is developed based on the concept of first order shear deformation theory (FSDT) in order to attempt the post-buckling solution for relatively thick composite plates subjected to uniform end-shortening. The main advantage of the semi-energy finite strip method (FSM) is that it is based on the closed form solution of von Karman’s compatibility equation in order to derive the analytical shape functions for the in-plane displacements fields. The developed finite strip method is applied to analyze the post buckling behavior of a relatively thick anti-symmetric cross-ply composite plate with clamped out-of-plane boundary conditions at its loaded ends. The results are discussed in detail and compared with those obtained from finite element method (FEM) of analysis. The study of the results has provided confidence in the validity and capability of the developed finite strip in handling post-buckling problem of relatively thick laminated plates.

A cell-based smoothed finite element formulation for viscoelastic laminated composite plates considering hygrothermal effects

2020 ◽  
pp. 002199832098005
Author(s):  
Sy-Ngoc Nguyen ◽  
Tam T Truong ◽  
Maenghyo Cho ◽  
Nguyen-Thoi Trung
Keyword(s):  
Finite Element ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Integral Form ◽  
Complex Stress ◽  
Laminated Plates ◽  
Element Formulation ◽  
Composite Laminated Plates ◽  
Smoothed Finite Element Method

In the present study, the viscoelastic analysis is investigated for composite laminated plates using a smoothed finite element method called cell/element based smoothed discrete shear gap method. Moreover, the hygrothermal effects is considered on the viscoelastic responses of composite laminated plates. The first-order shear deformation theory is employed due to its simplicity and accuracy. With the help of the convolution theorem in Laplace transformation, the complex stress-strain relationship in integral form is simplified to linear in transformed domain. Therefore, all computing procedures are performed in the transformed domain and then, using inverse techniques (Fast Fourier Transform) to converted back to the real-time domain. The study provides an effective computational tool to analyze the viscoelastic response of laminated composite taking into account the influence of the time and hygrothermal effects.

Free vibration analysis of symmetrically laminated composite circular plates with curvilinear fibers

2017 ◽  
Vol 24 (1) ◽  
pp. 111-121 ◽  
Author(s):  
Ahmed Guenanou ◽  
Abderrahim Houmat
Keyword(s):  
Free Vibration ◽  
Fiber Orientation ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Free Vibration Analysis ◽  
Published Data ◽  
Circular Plates ◽  
Simply Supported ◽  
Curvilinear Fibers

AbstractThe free vibration analysis of symmetrically laminated composite circular plates with curvilinear fibers is performed using the first-order shear deformation theory along with a curved hierarchical square finite element. The blending function method is used to describe accurately the geometry of the circular plate. The hierarchical shape functions are constructed from Legendre orthogonal polynomials. The element stiffness and mass matrices are integrated numerically by means of the Gauss-Legendre quadrature. The equations of motion are derived using Lagrange’s method. Results for the fundamental frequency are obtained for clamped and soft simply supported laminated composite circular plates with E-glass, graphite, and boron curvilinear fibers in epoxy matrices. The element is validated by means of the convergence test and comparison with published data for isotropic and laminated composite circular plates with rectilinear fibers. Contour plots of frequency as a function of fiber orientation angles for laminated composite circular plates with curvilinear fibers are presented. The fiber material and boundary conditions are shown to influence the distribution of frequency throughout the design space. Frequency curves as a function of fiber orientation angles for the first five modes of laminated composite circular plates with curvilinear fibers are also presented. They reveal that none of the first five modes of clamped and soft simply supported laminates is affected by crossing but modes 3 and 4 of clamped graphite/epoxy and boron/epoxy laminates are affected by veering.

scholarly journals Mode frequency analysis of antisymmetric angle-ply laminated composite stiffened hypar shell with cutout

2019 ◽  
Vol 23 (1) ◽  
pp. 162-171
Author(s):  
Puja Basu Chaudhuri ◽  
Anirban Mitra ◽  
Sarmila Sahoo
Keyword(s):  
Free Vibration ◽  
Natural Frequency ◽  
Frequency Analysis ◽  
Fiber Orientation ◽  
Orientation Angle ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Mode Frequency ◽  
Thickness Ratio ◽  
Fiber Orientation Angle

Abstract This article deals with finite element method for the analysis of antisymmetric angle-ply laminated composite hypar shells (hyperbolic paraboloid bounded by straight edges) that applies an eight-noded isoparametric shell element and a three-noded beam element to study the mode-frequency analysis of stiffened shell with cutout. Two-, 4-, and 10-layered antisymmetric angle-ply laminations with different lamination angles are considered. Among these, 10-layer antisymmetric angle-ply shells are considered for elaborate study. The shells have different boundary conditions along its four edges. The formulation is based on the first-order shear deformation theory. The reduced method of eigen value solution is chosen for the undamped free vibration analysis. The first five modes of natural frequency are presented. The numerical studies are conducted to determine the effects of width-to-thickness ratio (b/h), degree of orthotropy (E11/E22), and fiber orientation angle (θ) on the nondimensional natural frequency. The results reveal that free vibration behavior mainly depends on the number of boundary constraints rather than other parametric variations such as change in fiber orientation angle and increase in degree of orthotropy and width-to-thickness ratio.

Fiber Orientation Angles Optimization for Maximum Fundamental Frequency of Laminated Composite Plates by the Genetic Algorithm and Meshless Method

2014 ◽  
Vol 709 ◽  
pp. 130-134
Author(s):  
Feng Wang ◽  
Wei Ping Zhao ◽  
Song Xiang
Keyword(s):  
Genetic Algorithm ◽  
Fundamental Frequency ◽  
Fiber Orientation ◽  
Meshless Method ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Plates ◽  
Laminated Composite Plates ◽  
Fundamental Frequencies ◽  
Design Variables

Fiber orientation angles optimization is carried out for maximum fundamental frequency of clamped laminated composite plates using the genetic algorithm. The meshless method is utilized to calculate the fundamental frequency of clamped laminated composite plates. In the present paper, the maximum fundamental frequency is an objective function; design variables are a set of fiber orientation angles in the layers. The examples of square laminated plates are considered. The results for the optimal fiber orientation angles and the maximum fundamental frequencies of the 2-layer plates are presented.

scholarly journals Analysis of buckling phenomenon of rectangular laminated plates with a hole under different boundary conditions

2018 ◽  
Vol 149 ◽  
pp. 02013
Author(s):  
Ahmed El Bouhmidi ◽  
Mohamed Rougui
Keyword(s):  
Boundary Conditions ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Laminated Plates ◽  
Element Analysis ◽  
Different Boundary Conditions ◽  
First Order ◽  
Various Boundary Conditions ◽  
Buckling Behavior ◽  
Ply Orientation

In this research, buckling behavior of perforated rectangular plate of symmetric and anti-symmetric laminated composite is investigated based on Finite element analysis. The presence of hole may cause redistribution of stresses in plates with reduction of stability. The aim of the current paper is to find critical buckling load by using the (FSDT) first-order shear deformation theory in concomitance with the variational energy method. The load depends on many factors like as diameter of circular hole, different boundary conditions, lay-up sequences, length/thickness ratio and angle of ply orientation. The result is shown in graphical forms for various boundary conditions.

Application of the Method of Reverberation Ray Matrix to the Early Short Time Transient Responses of Stiffened Laminated Composite Plates

2012 ◽  
Vol 79 (4) ◽  
Author(s):  
Feng-Ming Li ◽  
Chun-Chuan Liu ◽  
Sheng Shen ◽  
Wen-Hu Huang
Keyword(s):  
Dynamic Models ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Plates ◽  
Laminated Plate ◽  
Laminated Composite Plates ◽  
Transient Responses ◽  
Transient Wave ◽  
Short Time

The method of reverberation ray matrix (MRRM) is extended to research the transient wave propagation and early short time transient responses of the stiffened laminated composite plates subjected to impact loads. The rib-stiffened laminated plates are modeled as the coupling systems in which the flexural motion for the laminated plate is considered, and the flexural and torsional motions are taken into account for the laminated stiffeners, which are modeled as the beams. The dynamic models of the laminated plates and beams in the Laplace phase space are established based on the first order shear deformation theory (FSDT). The reverberation ray matrix is determined by the continuous and boundary conditions of the stiffened laminated plate. The transient response corresponding to each ray group is calculated by the FFT algorithm. From the numerical results, it is seen that the early short time transient accelerations of the stiffened laminated plates are very large, while the early short time transient displacements are very small. Furthermore, the influences of the stiffeners and different impulse signals on the early short time transient responses of the stiffened laminated plates are also studied.

scholarly journals Bending and free vibration behaviors of composite plates using the C0-HSDT based four-node element with in-plane rotations

2020 ◽  
Vol 14 (1) ◽  
pp. 42-53
Author(s):  
Huynh Huu Tai ◽  
Nguyen Van Hieu ◽  
Vu Duy Thang
Keyword(s):  
Free Vibration ◽  
Degrees Of Freedom ◽  
Numerical Solutions ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Plates ◽  
Correction Factors ◽  
Quadrilateral Plate ◽  
Bending Problems

In this paper the smoothed four-node element with in-plane rotations MISQ24 is combined with a C0-type higher-order shear deformation theory (C0-HSDT) to propose an improved linear quadrilateral plate element for static and free vibration analyses of laminated composite plates. This improvement results in two additional degrees of freedom at each node and require no shear correction factors while ensuring the high precision of numerical solutions. Composite plates with different lay-ups, boundary conditions and various geometries such as rectangular, skew and triangular plates are analyzed using the proposed element. The obtained numerical results are compared with those from previous studies in the literature to demonstrate the effectiveness, the reliability and the accuracy of the present element. Keywords: composite laminated plates; bending problems; free vibration; C0-HSDT; MISQ24.

Free vibration analysis of laminated composite plates with elastically restrained edges using FEM

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Avadesh Sharma ◽  
N. Mittal
Keyword(s):  
Free Vibration ◽  
Vibration Analysis ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Free Vibration Analysis ◽  
Composite Plates ◽  
Laminated Plates ◽  
Laminated Composite Plates ◽  
Elastically Restrained Edges ◽  
Elastically Restrained

AbstractThe application of FEM is shown for free vibration analysis of moderately thick laminated composite plates with edges elastically restrained against translation and rotation. The governing equations employed are based on the first order shear deformation theory including the effects of rotary inertia. Several combinations of translational and rotational elastic edge constraints are considered. Convergence study with respect to the number of nodes has been carried out and the results are compared with those from past investigations available only for simpler problems. Angle-ply and cross-ply laminates with different thickness-to-length ratios are examined. Comparisons are made with results for thin as well as moderately thick laminated plates.

Dynamic analysis of a composite beam subjected to a moving load

2009 ◽  
Vol 223 (7) ◽  
pp. 1543-1554 ◽  
Author(s):  
M J Rezvani ◽  
Karami M Khorramabadi
Keyword(s):  
Dynamic Analysis ◽  
Composite Beam ◽  
Moving Load ◽  
Equations Of Motion ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Bending Moment ◽  
Axial Direction ◽  
Transformation Method ◽  
Concentrated Load

In this article, the dynamic analysis of an infinite Timoshenko beam made of a laminated composite located on a generalized Pasternak viscoelastic foundation is studied. The beam is subjected to a moving concentrated load. It is assumed that the mechanical properties of the beam change in the direction of the beam thickness but remain constant in the axial direction. Closed-form steady-state solutions, based on the first-order shear deformation theory, are developed. By selection of an appropriate displacement field for the composite beam, and using the principle of total minimum potential energy, the governing partial differential equations of motion are obtained and solved through a complex infinite Fourier transformation method. The results are introduced in terms of deflection, bending moment, shear force, and stress. In addition, the effects of stiffness, shear layer viscosity coefficients of foundation, velocity of the moving load, number of layers, and various angles of layers over the beam response are studied. For some specific cases, the results are compared with those presented in some other published papers, with which good agreements are observed.

Sign in / Sign up

Export Citation Format

Share Document