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In this paper, the effects of different composite plates on the healing of femoral fractures were studied by numerical simulation. The healing model of femoral fracture was established by ABAQUS display solver. Based on the fuzzy logic theory, the process of callus differentiation at femoral fracture was considered under the joint action of biological variables and mechanical stimulation, and the healing process of femur was simulated. Compare the stress on the screw, concentration of callus bone and cartilage, and callus healing performance of the carbon/epoxy composite (WSN3k) plate, glass/polypropylene composite (Twintex) plate, and stainless steel plate at various stages of bone healing, and investigate the impact of composite plates on the bone healing process. The results showed that the modulus of the plate had a notable impact on bone healing. Compared to stainless steel plate, the composite plate (due to its lower stiffness) exhibiting superior healing performance. Altering the sequence of composite laminates may modify the bone healing efficiency, and the wsn3k [0] 18 composite plate exhibits superior healing performance. [Display omitted] [ABSTRACT FROM AUTHOR]

Two complex bridges were recently completed using the concept of composite plate design. The first bridge to use this method, the Saint Lazare Bridge, crosses the busiest railway network in the city of Paris. The bridge consists of a 125-m-long steel box deck with a deck width of 17.5 m resting on V-shaped piers. The thickness of the concrete slab is 120 mm. The second bridge, currently under construction, is the Guerville Viaduct. This viaduct is a 360-m-long concrete-steel composite bridge with two I-shaped girders linked together by floor beams. The design of the central part of the deck, which is governed by a central span length of 116.5 m, requires a lighter and thinner slab than the typical reinforced concrete top slab. This led to the use of a composite plate that is 160 mm thick for the 157-m central part of the bridge. This paper presents the general design of both bridges along with the specific methodologies and calculations used for the composite deck plate designs. [ABSTRACT FROM AUTHOR]

In this paper the geometrically nonlinear continuum plate finite element model, hitherto not reported in the literature, is developed using the total Lagrange formulation. With the layerwise displacement field of Reddy, nonlinear Green-Lagrange small strain large displacements relations (in the yon Karman sense) and linear elastic orthotropic material properties for each lamina, the 3D elasticity equations are reduced to 2D problem and the nonlinear equilibrium integral form is obtained. By performing the linearization on nonlinear integral form and then the discretization on linearized integral form, tangent stiffness matrix is obtained with less manipulation and in more consistent form, compared to the one obtained using laminated element approach. Symmetric tangent stiffness matrixes, together with internal force vector are then utilized in Newton Raphson's method for the numerical solution of nonlinear incremental finite element equilibrium equations. Despite of its complex layer dependent numerical nature, the present model has no shear locking problems, compared to ESL (Equivalent Single Layer) models, or aspect ratio problems, as the 3D finite element may have when analyzing thin plate behavior. The originally coded MATLAB computer program for the finite element solution is used to verify the accuracy of the numerical model, by calculating nonlinear response of plates with different mechanical properties, which are isotropic, orthotropic and anisotropic (cross ply and angle ply), different plate thickness, different boundary conditions and different load direction (unloading/loading). The obtained results are compared with available results from the literature and the linear solutions from the author's previous papers. [ABSTRACT FROM AUTHOR]

In the present paper equivalent single layer (ESL) theory has employed with finite element method to describe the free vibration analysis of delaminated composite plates. Based on the first order shear deformation theory (FSDT) and finite element formulation, the work is fully concentrated on the free vibration analysis of delaminated composite plates. Two types of boundary conditions which are simply supported (S-S-S-S) and cantilever type (C-F-F-F) have taken for the analysis. The present work has also calculated the deformation at different places in composite plate; this is fully analytical and computational approach. Result is validated with the various references presented on the literature survey [ABSTRACT FROM AUTHOR]

A meshfree radial point interpolation method for free vibration analysis of laminated composite plates is presented in this paper. The idea approach bases on integrating a layerwise theory with the RPIM shape function constructed by the modified Gaussian function. In the layerwise theory, proposed by Ferreira A.J.M. [1] in 2005, the displacement field is assumed first-order shear deformation theory (FSDT) with independent rotations in each layer, and imposed displacement continuity at contact position of the layers interfaces. Hereby, that easily improves the accuracy of transverse shear stresses and the using of shear correction factors is not required. The high performances of present method are considered by investigating characteristic properties of laminated composite through numerical examples. The obtained results are discussed and compared with other previous solutions in the literature. [ABSTRACT FROM AUTHOR]

In this paper, a model strain energy based method and an improved differential evolution algorithm are used to locate and quantify damage on the laminated composite plate. Firstly, the modal strain energy based method is employed to identify a set of potential damaged elements. Then the improved differential evolution algorithm is utilized to minimize a mode shape error with the damage variables to indicate the extent of elements defined in the previous task. The numerical examples carry out a three-layer square laminated composite plate with two damaged elements. In addition, the effect of noise on the accuracy of damage localization is also investigated. [ABSTRACT FROM AUTHOR]

The electromechanical impedance damage detection method for composite plates is presented in this paper using piezoelectric materials. The structural damage is characterised by the admittance signals obtained from the piezoelectric materials. The results obtained in this study show that the resonance frequency will change if the damage occurs. The maximum amplitude value of the conductance without damage is larger than that with damage. The amplitude value increases as the radius of the damage holes increases. Furthermore, according to the admittance signals of the two PZT patches, the PZT is more sensitive to the damage when it is closer to the damage. The root mean square deviation damage index based on the admittance signals can also effectively reflect the damage information in the composite plate. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of the influence of the angular arrangement of laminas on the buckling force of rectangular composite plates. The article presents a general, simple analytical method of buckling load determination and finding the best arrangement in terms of the highest stiffness in the prebuckling state. Some special characteristic cases of arrangements in an eight layered GFRP laminate are assumed, and buckling force as a function of the arrangement is investigated by finding proper maxima. Results for some characteristic lay-ups are compared with FEM and results found in literature. [ABSTRACT FROM AUTHOR]

In this paper, the coupled problem of planar acoustic wave propagation through the double-layer composite plate containing the second layer from damping material with high logarithmic decrement is examined. Aerohydrodynamic interaction between plate and external acoustic environment is defined by three-dimensional wave equations, whilst mechanical behaviour of doublelayered plate is examined with model based on classical Kirchhoff-Love's hypothesis. Exact analytical solutions are given for plates with simply supported edges. On the basis of given solutions, parameters for second layer, which lead substantially damping of plate vibrations are found in the case of acoustic loading at resonant modes. [ABSTRACT FROM AUTHOR]

This paper presents a new four-node composite element, which incorporates nd delaminations through its thickness. Based on the extended finite element method (X-FEM) technology, the element is particularized on a CLT (classical laminate theory). Delamination is considered in the kinematic equations with additional degrees of freedom. The result is a four-node quadrilateral element requiring only two single FEM (finite element method) formulations, a bending one and a membrane one. An important result is that this formulation has the same accuracy as when separate elements are considered ("four region approach" ). It is furthermore proven that the delaminated element passes the "patch test" if the selected FEM formulations to build the element pass the test in the pure single problems, making this methodology very attractive to develop other fractured elements. To illustrate this result, two benchmark problems were studied: first a complete delaminated cantilever plate, and second a complete delaminated circular plate. The element was tested in the context of SHM (structural health monitoring). Frequency shifts, damage indexes, and changes in mode shapes and frequency response functions (FRF) were obtained to quantify the severity of damage due to delaminatio. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, static behavior of functionally graded carbon nanotube reinforced polymer composite plate under non uniform elevated temperature fields has been investigated using finite element method. The effective material properties of the composite plate are obtained using the extended rule of mixture along with carbon nanotube efficiency parameters (to include size-dependent material properties). Parameter studies are carried out to analyze influence of boundary conditions of the plate, type of functional grading of the carbon nanotube and type of non uniform thermal loading on static behavior of the functionally graded carbon nanotube reinforced composite plate. It is found that static behavior of the composite plate has been significantly influenced by nature of temperature field and nature of functional grading of carbon nanotubes. Static bending deflection of the plate increases with volume fraction of the carbon nanotube except for unsymmetrical distribution of carbon nanotube. [Copyright &y& Elsevier]

In this paper, the nonlinear free vibration stochastic characteristic of a smart laminated composite plate having random system properties is presented. The transverse shear effects have been included in the system equation in the frame work of higher order shear deformation theory. The analysis uses the Green-Lagrange nonlinear strain displacement relationship to model geometric nonlinearity. The direct iteration approach is used to handle deterministic geometric nonlinearity, and the perturbation approach is employed to handle the randomness in the system properties. Mean and variance of the random natural frequencies have been obtained by employing a C° isoparametric nonlinear finite element model. Comparisons with the published results show the accuracy of the proposed procedure. A few results covering various features have been presented for a laminated composite plate with different boundary conditions. [ABSTRACT FROM AUTHOR]

This paper deals with an experimental investigation to study the effect of fibre content on the stability of composite plates with various aspect ratios. Epoxy based glass fibre reinforced composite plates with aspect ratio varying from 0.4 to 1 and with volume fractions of 0.36, 0.4, 0.46, 0.49 and 0.55 are used for the investigation. From the study it is observed that for plate with aspect ratio of 0.5 and 0.4 there is no buckling and the plate got crushed at the middle. As the volume fraction increases the buckling load also increases to a limit and then began to reduce with further increase in fibre content. The optimum range of fibre content for maximum stability is found between 0.49 and 0.55. Polynomial expressions are developed for the study of buckling behaviour of composite plates with different volume fractions in terms of load and aspect ratio. [ABSTRACT FROM AUTHOR]

In this paper, the thermal buckling analysis of rectangular composite laminated plates is investigated using the Differential Quadrature (DQ) method. The composite plate is subjected to a uniform temperature distribution and arbitrary boundary conditions. The analysis takes place in two stages. First, pre-buckling forces due to a temperature rise are determined by using a membrane solution. In the second stage, the critical temperature is predicted based on the first-order shear deformation theory. To verify the accuracy of the method, several case studies were used and the numerical results were compared with those of other published literatures. Moreover, the effects of several parameters such as aspect ratio, fiber orientation, modulus ratio, and various boundary conditions on the critical temperature were examined. The results confirm the efficiency and accuracy of the DQ method in dealing with this class of engineering problems. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the bending and vibration analysis of moderately damaged coupled shear wall structures with externally bonded carbon fiber-reinforced polymer (CFRP) sheets. In the analytical formulation, the adherent and the adhesive layers are all modelled as shear walls, using the mixed finite-element method (FEM). The anisotropic damage model is adopted to describe the damage extent of the RC coupled shear walls. A free vibration analysis is carried out to determine the frequencies of multi-storey strengthened shear wall structures with openings. Test problems are conducted to demonstrate the accuracy and effectiveness of the proposed method. Numerical results are presented to show the performance of reinforced concrete coupled shear wall structures bonded with composite plates in which a damaged RC shear wall with openings strengthened by a thin steel sheets is treated as a comparator. The effects of damage extent and of the bonded sheets on the bending and vibration characteristics of damaged RC coupled shear wall structures are also studied. [Copyright &y& Elsevier]

Composite laminated structures supported on elastic foundations are being increasingly used in a great variety of engineering applications. Composites exhibit larger dispersion in their material properties compared to the conventional materials due to large number of parameters associated with their manufacturing and fabrication processes. And also the dispersion in elastic foundation stiffness parameter is inherent due to inaccurate modeling and determination of elastic foundation properties in practice. For a better modeling of the material properties and foundation, these are treated as random variables. This paper deals with effects of randomness in material properties and foundation stiffness parameters on the free vibration response of laminated composite plate resting on an elastic foundation. A C0 finite element method has been used for arriving at an eigen value problem. Higher order shear deformation theory has been used to model the displacement field. A mean centered first order perturbation technique has been employed to handle randomness in system properties for obtaining the stochastic characteristic of frequency response. It is observed that small amount of variations in random material properties and foundation stiffness parameters significantly affect the free vibration response of the laminated composite plate. The results have been compared with those available in the literature and an independent Monte Carlo simulation. [ABSTRACT FROM AUTHOR]