High-order layerwise finite element for the damped free-vibration response of thick composite and sandwich composite plates

2008 ◽  
Vol 77 (11) ◽  
pp. 1593-1626 ◽  
Author(s):  
Theofanis S. Plagianakos ◽  
Dimitris A. Saravanos
2012 ◽  
Vol 21 (1) ◽  
pp. 096369351202100 ◽  
Author(s):  
Turan Ercopur ◽  
Binnur Goren Kiral

This paper deals with the finite element analysis of free vibration response of the delaminated composite plates. Free vibration analysis is performed by using ANSYS commercial software developing parametric input files. Natural frequency values and associated mode shapes of E-glass/epoxy composite delaminated plates are determined. Effects of delamination shape, dimension and location on the natural frequency and associated mode shapes are investigated and for the purpose of the observing the effect of the boundary conditions, cantilever and clamped-pinned delaminated composite plates are taken into consideration. Comparisons with the results in literature verify the validity of the developed models in this study. It is observed that the natural frequency decreases in the existence of the delamination and level of the decrease depends on the dimension, shape and location of the delamination.


2019 ◽  
Vol 37 (5) ◽  
pp. 1597-1616 ◽  
Author(s):  
Guangxin Wang ◽  
Lili Zhu ◽  
Ken Higuchi ◽  
Wenzhong Fan ◽  
Linjie Li

Purpose The purpose of this paper is to propose and analyze the free vibration response of the spatial curved beams with variable curvature, torsion and cross section, in which all the effects of rotary inertia, shear and axial deformations can be considered. Design/methodology/approach The governing equations for free vibration response of the spatial curved beams are derived in matrix formats, considering the variable curvature, torsion and cross section. Frobenius’ scheme and the dynamic stiffness method are applied to solve these equations. A computer program is coded in Mathematica according to the proposed method. Findings To assess the validity of the proposed solution, a convergence study is carried out on a cylindrical helical spring with a variable circular cross section, and a comparison is made with the finite element method (FEM) results in ABAQUS. Further, the present model is used for reciprocal spiral rods with variable circular cross section in different boundary conditions, and the comparison with FEM results shows that only a limited number of terms in the results provide a relatively accurate solution. Originality/value The numerical results show that only a limited number of terms are needed in series solutions and in the Taylor expansion series to ensure an accurate solution. In addition, with a simple modification, the present formulation is easy to extend to analyze a more complicated model by combining with finite element solutions or analyze the transient responses and stochastic responses of spatial curved beams by Laplace transformation or Fourier transformation.


2011 ◽  
Vol 471-472 ◽  
pp. 1177-1183
Author(s):  
Tasneem Pervez ◽  
F.K.S. Al-Jahwari ◽  
Abdennour Seibi

Free vibration analysis of arbitrarily laminated plates of quad, penta and hexagonal shapes, which have combinations of clamped, simply supported and free edge conditions is performed. The finite element formulation is based on first and higher order shear deformation theories to study the free vibration response of thick laminated composite plates. A finite element code is developed incorporating shear deformation theories using an 8-noded serendipity element. The effect of plate shape, arbitrary lamination and different edge conditions on natural frequencies and mode shapes are investigated. A systematic study is carried out to determine the influence of material orthotropy and aspect ratio on free vibration response. For various cases, the comparisons of results from present study showed good agreement with those published in the literature.


2006 ◽  
Vol 06 (01) ◽  
pp. 121-138 ◽  
Author(s):  
Z. I. SAKKA ◽  
J. A. ABDALLA ◽  
H. R. H. KABIR

The free vibration response of shear-flexible moderately-thick orthotropic cylindrical shell panels, with fixed edges, is investigated using an analytical approach. The governing partial differential equations are developed based on Sander's kinematics and are solved using generalized Navier's with a boundary continuous double Fourier series expansion. The frequencies and mode shapes from the analytical solution for various parametric ratios, including degree of orthotropy (stiffness ratio), radius-to-segment ratio and segment-to-thickness ratio are compared with the finite element solutions that are based on an eight-node 48 degrees of freedom shell element. The rate of convergence of the analytical solution method with respect to the number of Fourier series terms, for various parametric ratios, is presented. The results of the analytical solution are very comparable to that of the finite element solution. It is clear that the presented analytical solution can be used as a benchmark to calibrate and validate numerical and finite element solutions that usually involve approximation to shell theories.


1999 ◽  
Author(s):  
Kishore Pochiraju

Abstract This paper presents a sandwich composite architecture suitable for embedding MEMS-based accelerometers for long-term vibration monitoring or to act as sensors in adaptive structures. The presented architecture is designed around multi-axis accelerometers and temperature sensors that are commercially available. These devices also integrate sophisticated sensor compensation and data acquisition hardware into a single integrated circuit chip package. The paper presents the stiffness modeling of a sandwich composite with embedded accelerometers based on classical lamination theory. The first order shear deformation theory is used to compute the free vibration response of the sandwich composite. Solutions are presented for the free-vibration response of the sandwich beam under fixed-free boundary conditions. Results presented also include the response obtained from the MEMS-accelerometer when coupled to a thick cross-ply laminate under fixed-free boundary conditions.


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