DYNAMIC ANALYSIS OF STIFFENED AND UNSTIFFENED COMPOSITE PLATES (original) (raw)
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TJPRC, 2013
In this work, a suggested analytical solution for dynamic analysis of stiffened and un stiffened composite plates subjected to an-axial dynamic loading is presented. The dynamic analysis for equations of motion are solved by using the modal analysis of forced vibration. The results are the response and stress in x and y-direction for symmetric and antisymmetric, cross-ply and angle-ply, laminated plates subjected to the dynamic axial loading conditions of type. In addition, the results for displacement and stresses are presented showing the effect of plate side-to-thickness ratio, aspect ratio, material orthotropy, the effect of boundary conditions, number of layers of laminated, and lamination scheme and are confirmed with other solutions results. Also results for displacement and stresses of stiffened laminated plates are presented showing the effect of number of stiffeners, high to width of stiffener ratio, high of stiffener, the width of stiffener, and the stiffener properties.
Free Vibration Analysis of Stiffened Laminated Composite Plates
International Journal of Computer Applications, 2016
Stiffened Laminated composite plates are widely used in the aerospace, civil, marine, and automotive industries due to their high specific stiffness and strength, excellent fatigue resistance, long durability and many other superior properties compared to ordinary plates. In this paper, the effect of stiffener configuration, number of layers and boundary conditions on the free vibration response of stiffened laminated composite plates are examined with respect to natural frequencies and mode shapes. Six rectangular stiffeners configurations models are used with two types of boundary conditions which are simply and clamped supported. Comparative study is conducted to investigate the effect of stiffener configuration, number of layers and boundary conditions on the free vibration response of stiffened laminated composite plates using the finite element system ANSYS16.
Static and Dynamic Analysis of Composite Laminated Plate
This work presents a static and dynamic analysis of Graphite /Epoxy composite plates. In the present work the behavior of laminated composite plates under transverse loading using an eight-node diso-parametric quadratic element based on First Order Shear Deformation Theory was studied, the element has six degrees of freedom at each node: translations in the nodal x, y, and z directions and rotations about the nodal x, y, and z axes. The static analysis includes the parametric studies on laminated plates to estimate the maximum deflection. The parametric study represented by variation in (aspect ratio, layer orientation, layer number, dimension of the plate and mesh size). The modeling of the plates was done by using ANSYS 12.0, and the results were compared with Finite Element Method code.The dynamic part of this study represented by evaluating the natural frequency of the plates. The boundary conditions considered in static and dynamic study, are simply supported and clamped boundary condition. In this study investigations were carried out on both square and rectangular composite laminated plates. The study start with isotropic plate of mild steel, and followed with orthotropic plate of Graphite/Epoxy composite .The results obtained from ANSYS program as well as Finite Element Method code, show a good agreement with the experimental results. The minimum deflection was found at an angle of 15 degree for clamped plate, and in case of simply supported plate the minimum deflection was found for angle 45 degree. It is also observed that the deflection for clamped boundary condition is less than in simply supported boundary condition for both isotropic and orthotropic plates. In isotropic plate the deflection in clamped plate is about 50% of simply supported. And for orthotropic plate the deflection for clamped is about (25 to 30)% of simply supported.
Application of the dynamic stiffness method in the vibration analysis of stiffened composite plates
Procedia Engineering, 2017
Composite laminates are nowadays extensively applied in many engineering disciplines. Free vibration characteristics of such structures are not always easy to predict by using conventional finite element method (FEM). As an alternative, the dynamic stiffness method (DSM) can be applied to predict free vibration characteristics of composite plate assemblies, especially in mid and high frequency ranges. Key feature of the DSM is the dynamic stiffness element (DSE) and its dynamic stiffness matrix, derived from the exact solution of the governing equations of motion in the frequency domain. Consequently, the structural discretization is influenced only by the change in the geometrical and/or material properties of the structure. The number of unknowns is significantly decreased in comparison with the FEM, without losing the accuracy and reliability of the results. In the paper, the DSE based on the higher order shear deformation theory (HSDT) is applied to study free vibration analysis of composite stiffened plates. The numerical analysis has been carried out through an illustrative example in order to check the accuracy of the proposed method. The influence of side-to-thickness ratio on the free vibration characteristics of stiffened plate has been studied numerically. The results are validated using the available analytical data as well as with the FEM solutions.
Analysis of laminated composite plates based on different shear deformation plate theories
Structural Engineering and Mechanics, 2020
A finite strip formulation was developed for buckling and free vibration analysis of laminated composite plates based on different shear deformation plate theories. The different shear deformation theories such as Zigzag higher order, Refined Plate Theory (RPT) and other higher order plate theories by variation of transverse shear strains through plate thickness in the parabolic form, sine and exponential were adopted here. The two loaded opposite edges of the plate were assumed to be simply supported and remaining edges were assumed to have arbitrary boundary conditions. The polynomial shape functions are applied to assess the in-plane and out-of-plane deflection and rotation of the normal cross-section of plates in the transverse direction. The finite strip procedure based on the virtual work principle was applied to derive the stiffness, geometric and mass matrices. Numerical results were obtained based on various shear deformation plate theories to verify the proposed formulatio...
ANALYSIS OF COMPOSITE LAMINATED PLATES
The convergence and accuracy of the Dynamic Relaxation (DR) solutions for elastic large deflection response are established by comparison with various exact and approximate solutions. New numerical results are generated for uniformly loaded square laminated plates which serve to quantify the effects of shear deformation, length to thickness ratio, number of layers, material anisotropy and fiber orientation. It was found that linear analysis seriously over predicts deflection of plates. The shear deflection depends greatly on a number of factors such as length to thickness ratio, degree of anisotropy and number of layers. As the degree of anisotropy increases, the plate becomes stiffer and when it is greater than a critical value, the deflection becomes virtually independent on the degree of anisotropy. It was also found that deflection of plates depends on the angle of orientation of individual plies and the size of load applied.
This paper represents the laminated plate growing researc to dynamic loading in their working life and vibration affects working life of the structure predict of the free vibratio displacements of each layer are expressed in terms of Layerwise HSDT the thickness. The displacement field of present theory contains nine unknowns, as in the higher order shear deformation finding the analytical solutions. supported cross been obtained by using Layerwise HSDT. It is sh can provide accurate results. comparing it with various available results in the literature. The results show that the present model performs better than all the exist theories. ABSTRACT This paper represents the aminated plate growing researc to dynamic loading in their working life and vibration affects working life of the structure. Layerwise predict of the free vibratio displacements of each layer are expressed in terms of Layerwise HSDT the thickness. The displacement field of present theory contains nine unknowns, as in the higher order shear deformation finding the analytical solutions. supported cross been obtained by using Layerwise HSDT. It is sh can provide accurate results. comparing it with various available results in the literature. The results show that the present model performs better than all the exist heories. This paper represents the aminated plate. As we know that vibration and composite material are two main growing research topics now a days. Almost all the structural components subjected to dynamic loading in their working life and vibration affects working life of the Layerwise Higher Order Shear Deformation Theory (predict of the free vibratio displacements of each layer are expressed in terms of Layerwise HSDT the thickness. The displacement field of present theory contains nine unknowns, as in the higher order shear deformation finding the analytical solutions. supported cross-ply and anti been obtained by using Layerwise HSDT. It is sh can provide accurate results. comparing it with various available results in the literature. The results show that the present model performs better than all the exist IJMET/index.asp This paper represents the investigation As we know that vibration and composite material are two main h topics now a days. Almost all the structural components subjected to dynamic loading in their working life and vibration affects working life of the Higher Order Shear Deformation Theory (predict of the free vibration characteristics of laminated composite plates. displacements of each layer are expressed in terms of Layerwise HSDT the thickness. The displacement field of present theory contains nine unknowns, as in the higher order shear deformation finding the analytical solutions. Non ply and anti-symmetric angle been obtained by using Layerwise HSDT. It is sh can provide accurate results. The accuracy of the present theory is ascertained by comparing it with various available results in the literature. The results show that the present model performs better than all the exist asp 414 investigation on the response of a As we know that vibration and composite material are two main h topics now a days. Almost all the structural components subjected to dynamic loading in their working life and vibration affects working life of the Higher Order Shear Deformation Theory (n characteristics of laminated composite plates. displacements of each layer are expressed in terms of Layerwise HSDT the thickness. The displacement field of present theory contains nine unknowns, as in the higher order shear deformation theory Navier's solution method is used for Non-dimensional fundamental frequencies of simply symmetric angle-ply laminated composite plates have been obtained by using Layerwise HSDT. It is sh The accuracy of the present theory is ascertained by comparing it with various available results in the literature. The results show that the present model performs better than all the exist the response of a As we know that vibration and composite material are two main h topics now a days. Almost all the structural components subjected to dynamic loading in their working life and vibration affects working life of the Higher Order Shear Deformation Theory (n characteristics of laminated composite plates. displacements of each layer are expressed in terms of Layerwise HSDT the thickness. The displacement field of present theory contains nine unknowns, as in theory Navier's solution method is used for dimensional fundamental frequencies of simply-ply laminated composite plates have been obtained by using Layerwise HSDT. It is shown that the present Layerwise HSDT The accuracy of the present theory is ascertained by comparing it with various available results in the literature. The results show that the present model performs better than all the existing higher order shear deformation the response of a symmetric composite As we know that vibration and composite material are two main h topics now a days. Almost all the structural components subjected to dynamic loading in their working life and vibration affects working life of the Higher Order Shear Deformation Theory (HSDT n characteristics of laminated composite plates. displacements of each layer are expressed in terms of Layerwise HSDT the thickness. The displacement field of present theory contains nine unknowns, as in theory Navier's solution method is used for dimensional fundamental frequencies of simply ply laminated composite plates have own that the present Layerwise HSDT The accuracy of the present theory is ascertained by comparing it with various available results in the literature. The results show that the ing higher order shear deformation symmetric composite As we know that vibration and composite material are two main h topics now a days. Almost all the structural components subjected to dynamic loading in their working life and vibration affects working life of the HSDT) is used to n characteristics of laminated composite plates. displacements of each layer are expressed in terms of Layerwise HSDT functions of the thickness. The displacement field of present theory contains nine unknowns, as in theory Navier's solution method is used for dimensional fundamental frequencies of simply ply laminated composite plates have own that the present Layerwise HSDT The accuracy of the present theory is ascertained by comparing it with various available results in the literature. The results show that the ing higher order shear deformation symmetric composite As we know that vibration and composite material are two main h topics now a days. Almost all the structural components subjected to dynamic loading in their working life and vibration affects working life of the is used to The functions of the thickness. The displacement field of present theory contains nine unknowns, as in theory Navier's solution method is used for dimensional fundamental frequencies of simply ply laminated composite plates have own that the present Layerwise HSDT The accuracy of the present theory is ascertained by comparing it with various available results in the literature. The results show that the ing higher order shear deformation
Review on: Analysis of Laminated Composite Plate
In the present paper, basic terminology of laminated composite plates are discussed. Laminated composite plate structures find numerous applications in aerospace, military and automotive industries. The role of transverse shear is very important in composites, as the material is weak in shear due to its low shear modulus compared to extensional rigidity. Hence, an accurate understanding of their structural behavior is required, such as deflections and stresses. From the present Literature Review the effect of bending, buckling, thermal & hygrothermal on composite plates discussed and different theories like Classical Plate Theory, First Order Shear Deformation Theory, Higher order Shear Deformation Theory etc. for analysis of composite plate are mentioned.
Latin American Journal of Solids and Structures, 2016
In the present study, a simple trigonometric shear deformation theory is applied for the bending, buckling and free vibration of crossply laminated composite plates. The theory involves four unknown variables which are five in first order shear deformation theory or any other higher order theories. The in-plane displacement field uses sinusoidal function in terms of thickness coordinate to include the shear deformation effect. The transverse displacement includes bending and shear components. The present theory satisfies the zero shear stress conditions at top and bottom surfaces of plates without using shear correction factor. Equations of motion associated with the present theory are obtained using the dynamic version of virtual work principle. A closed form solution is obtained using double trigonometric series suggested by Navier. The displacements, stresses, critical buckling loads and natural frequencies obtained using present theory are compared with previously published results and found to agree well with those.
Vibration of thick laminated composite plates
Journal of Sound and Vibration, 1995
Two versions of a {1, 2} higher order laminate plate theory are derived for elastodynamics and used to compute natural frequencies and mode shapes for homogeneous and laminated plates. The theories include deformations due to transverse shear and transverse normal stretching and account for rotary and thickness-motion inertia. Analytic natural frequencies and mode shapes are obtained for thin and thick orthotropic and laminated simply supported plates and compared with exact solutions of three-dimensional elasticity, the higher and first order shear-deformable theories, and the classical laminate plate theory. Both versions of the present theory are shown to provide improved accuracy over other approximate theories when compared to elasticity theory, particularly for thick laminates and high frequency modes. The theory also accurately predicts the lowest thickness-stretch frequencies which cannot be obtained with first order shear-deformable theories. From the computational perspective, the theory is especially well-suited for generating simple and efficient displacement finite elements based on conventional C 0-continuous displacements and five degrees of freedom at each boundary node. An approximation scheme for a three-noded triangular plate element is also discussed, together with a numerical study demonstrating the element performance in relation to two commercial plate elements.