scholarly journals Effects of Delamination on Guided Waves in a Symmetric Laminated Composite Beam

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Seungwan Kim ◽  
Usik Lee
Keyword(s):  
Frequency Domain ◽  
Composite Beam ◽  
Guided Waves ◽  
Structural Integrity ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Element Model ◽  
Spectral Element ◽  
Composite Beams ◽  
Variation Method

For successful structural health monitoring and structural integrity evaluation of a laminated composite structure, it is important to study the effects of delamination on the propagations of the guided waves in a delaminated composite beam by using an accurate and computationally efficient method. Thus, we developed a “frequency-domain” spectral element model for the symmetric composite beams. First-order-shear-deformation-theory (FSDT) based Timoshenko beam theory and Mindlin-Herrmann rod theory are adopted for the flexural (bending) waves and axial (extensional) waves, respectively. A spectral element model is derived from the governing equations of motion by using the variation method in the frequency domain. After validating the accuracy of the proposed spectral element model, the model is used to investigate the effects of delamination on the propagation of guided waves in examples of composite beams.

Spectral Element Model for the PZT-Bonded Laminated Composite Beams

2012 ◽  
Vol 249-250 ◽  
pp. 838-841 ◽  
Author(s):  
Usik Lee ◽  
Il Wook Park ◽  
In Joon Jang
Keyword(s):  
Frequency Domain ◽  
Dynamic Stiffness ◽  
Laminated Composite ◽  
Element Model ◽  
Spectral Element ◽  
Composite Beams ◽  
Dft Theory ◽  
Shape Functions ◽  
Laminated Composite Beams ◽  
Dynamic Shape

This paper presents a spectral element model for the laminated composite beams with a surface-bonded PZT layer. The spectral element model represented by exact dynamic stiffness matrix is derived in the frequency-domain by using the frequency-dependent dynamic shape functions which are formulated from the free wave solutions satisfying the governing differential equations transformed into the frequency-domain by using the DFT theory. The performance of the present spectral element model is then evaluated by comparing its solutions with those obtained by using the conventional finite element model

STATIC AND DYNAMIC BEHAVIOUR OF LAMINATED COMPOSITE BEAMS

2001 ◽  
Vol 01 (04) ◽  
pp. 545-560 ◽  
Author(s):  
M. A. RAMOS LOJA ◽  
J. INFANTE BARBOSA ◽  
C. M. MOTA SOARES
Keyword(s):  
Cross Sections ◽  
Degrees Of Freedom ◽  
Three Dimensional ◽  
Shear Deformation Theory ◽  
Single Layer ◽  
Laminated Composite ◽  
Element Model ◽  
Composite Beams ◽  
Straight Beam ◽  
Transverse Stresses

A higher order shear deformation theory, assuming a non-linear variation for the displacement field, is used to develop a finite element model to predict static and free vibration behaviour of anisotropic multilaminated thick and thin beams. The model is based on a single-layer Lagrangean four-node straight beam element with fourteen degrees of freedom per node. It considers bending into two orthogonal planes, stretching and twisting to enable three-dimensional analysis of frames. The most common cross sections and symmetric and asymmetric lay-ups are studied. The behaviour of the model is tested on thin and thick isotropic and composite beams. Comparisons show that the model is accurate and versatile. The good performance of the present model is evident on the prediction of displacements, normal and transverse stresses and natural frequencies of thin and thick isotropic or anisotropic beam structures.

scholarly journals Flexural Interpretation of Simply Supported Laminated Composite Beam

2020 ◽  
Vol 8 (5) ◽  
pp. 3559-3565
Keyword(s):  
Shear Deformation ◽  
Composite Beam ◽  
Laminated Composite ◽  
Beam Theory ◽  
Composite Beams ◽  
Shear Stresses ◽  
Bending Stress ◽  
Simply Supported ◽  
Laminated Composite Beam ◽  
Laminated Composite Beams

In this Paper, the analysis of simply supported laminated composite beam having uniformly distributed load is performed. The solutions obtained in the form of the displacements and stresses for different layered cross ply laminated composite simply supported beams subjected uniformly distributed to load. Different aspect ratio consider for different results in terms of displacement, bending stress and shear stresses. The shear stresses are calculated with the help of equilibrium equation and constitutive relationship. Using displacement field including trigonometric function of laminated composite beams are derived from virtual displacement principle. There are axial displacement, transverse displacement, bending stress and shear stresses. In addition, Euler-Bernoulli (ETB), First order shear deformation beam theory (FSDT), Higher order shear deformation beam theory (HSDT) and Hyperbolic shear deformation beam theory (HYSDT) solution have been made for comparison and better accuracy of solutions and results of static analyses of laminated composite beams for simply supported laminated composite beam.

scholarly journals Free Vibration Analysis of Curved Laminated Composite Beams with Different Shapes, Lamination Schemes, and Boundary Conditions

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 1010 ◽  
Author(s):  
Bin Qin ◽  
Xing Zhao ◽  
Huifang Liu ◽  
Yongge Yu ◽  
Qingshan Wang
Keyword(s):  
Free Vibration ◽  
Boundary Conditions ◽  
Variational Approach ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Free Vibration Analysis ◽  
Composite Beams ◽  
Arbitrary Boundary ◽  
Correlated Parameters ◽  
Laminated Composite Beams

A general formulation is considered for the free vibration of curved laminated composite beams (CLCBs) with alterable curvatures and diverse boundary restraints. In accordance with higher-order shear deformation theory (HSDT), an improved variational approach is introduced for the numerical modeling. Besides, the multi-segment partitioning strategy is exploited for the derivation of motion equations, where the CLCBs are separated into several segments. Penalty parameters are considered to handle the arbitrary boundary conditions. The admissible functions of each separated beam segment are expanded in terms of Jacobi polynomials. The solutions are achieved through the variational approach. The proposed methodology can deal with arbitrary boundary restraints in a unified way by conveniently changing correlated parameters without interfering with the solution procedure.

Frequency optimization of laminated composite plates with different intermediate line supports

2012 ◽  
Vol 19 (3) ◽  
pp. 295-306 ◽  
Author(s):  
Umut Topal
Keyword(s):  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Element Model ◽  
Aspect Ratios ◽  
Feasible Direction Method ◽  
Isoparametric Finite Element ◽  
Optimization Routine ◽  
Frequency Optimization ◽  
Internal Line Supports

AbstractThis paper deals with frequency optimization of symmetrically laminated 4-layered angle-ply plates with one or two different intermediate line supports. The design objective is the maximization of the fundamental frequency and the design variable is the fiber orientation in the layers. The first order shear deformation theory and nine-node isoparametric finite element model are used for finding the natural frequencies of laminates. The modified feasible direction method is used for the optimization routine. For this purpose, a program based on FORTRAN is used. Finally, the numerical analysis is carried out to investigate the effects of location of the internal line supports, plate aspect ratios and boundary conditions on the optimal designs and the results are compared.

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