Solution For Composite Plates Research Articles

Linear 3D piezo-elasticity theory for static and free vibration analysis of piezoelectric/GOP/CNTs panels submerged in fluid

The objective of this study is to analyze the bending and free vibration analysis of a new type of smart hybrid FG composite plate integrated with piezoelectric layers that are submerged in fluid. The proposed composites for some layers are carbon nanotubes (CNTs) and for some other are graphene oxide powder (GOP), along with two layers of piezoelectric sensors and actuators. Furthermore, two distinct combinations, namely GOP/CNTs/GOP and CNTs/GOP/CNTs, are analyzed. To capture the structural response of the system, exact linear three-dimensional piezoelasticity theory is employed to derive a semi-analytic solution for composite plates of arbitrary thickness, thereby avoiding simplifications in constitutive relations. The computation of fluid interaction components is performed using the Rayleigh integral method, and the coupling of structural and fluid interactions in the equations is addressed without imposing constraints on fluid density or assuming a far-field approximation. Parametric studies are carried out for the first time to investigate the impact of dimension ratios, reinforced distributions, and weight fractions of nanofiller on the natural frequency and static behaviour of the novel hybrid submerged smart composites.

Influence of Double-Pulse Electrodeposition Parameters on the Performance of Nickel/Nanodiamond Composite Coatings

In this study, using 45# carbon steel as the substrate, a first experimental analysis was carried out on the polarisation behaviour of different component wattage plating solutions in order to determine the reasonable content of nanodiamond particles in a nickel/nanodiamond composite plating solution. Secondly, the effect of double-pulse forward and reverse duty cycle and reverse working time on the performance of nickel/nanodiamond composite plating was then investigated by testing the thickness, hardness and surface roughness of the composite plating and observing the surface micromorphology. The experimental results show that, when the content of nanodiamond particles in the plating solution is 5 g/L, the anti-pulse working time, forward and reverse pulse duty cycle of the double-pulse plating parameters are 20 ms, 0.3 and 0.2, respectively, and the composite plating layer prepared by double pulse has good comprehensive performance. This research work provides technical support for the optimisation of process parameters for the preparation of nickel/nanodiamond composite coatings by double-pulse electrodeposition.

Efficient Quadrature Solution for Composite Plates with Variable Thickness Resting on Non-Uniform and Nonlinear Elastic Foundation

Efficient Quadrature Solution for Composite Plates with Variable Thickness Resting on Non-Uniform and Nonlinear Elastic Foundation

Analytical frequency response solution for composite plates embedding viscoelastic layers

In this work analytical damped free-vibration and frequency response solutions are obtained for the analysis of composite plates structures embedding viscoelastic layers. On the basis of the Principle of Virtual Displacements, Layer-Wise models related to linear up to fourth order variations of the unknown variables in the thickness direction are treated. Analytical solutions using the Navier procedure are presented for the analysis of isotropic, cross-ply composite and simply-supported plate structures. The modelization of multilayered structure materials takes into account the composite material properties and the frequency dependence of the viscoelastic material. Various external loads are considered: closed form solution for bi-sinusoidal pressure, constant distributed pressure and concentrated loads. Several analyses are carried out to validate and demonstrate the accuracy and efficiency of the present formulation for the study of viscoelastic plates, taking into account different lamination sequences and different plate aspect ratios.

Predictions of the frequencies of bending-torsion coupled laminated composite plates with discontinuities: Novel analytical modeling and experimental validation

A novel analytical model that accurately represents the free vibration response of intact/damaged composite plates accounting for the bending-torsional coupling is developed. Unlike the existing models for the bending-torsion vibrations of composite plates, in the present model, the equations of motion are derived in an uncoupled form. It is then easier to derive analytical solutions for composite plates under coupled bending-torsion vibrations. In addition, for the first time, analytical solutions for the free bending and torsional vibrations of cantilever and clamped-clamped laminated composite plates with discontinuities including circular holes, rectangular holes, notches, and internal and edge cracks are easily obtained. Shifts in the natural frequencies due to discontinuities are modeled where the reductions in the plate stiffnesses are related to the amount of the energy release rate due to a defect formation. In order to verify the accuracy of the proposed model and the derived solutions, the proposed model is compared to the available conventional models. Moreover, experimental measurements of the free bending and torsional vibrations of carbon-fiber-laminated composite plates with circular holes is performed. A set of finite element analyses are carried out and compared to the experimental and the proposed model results. Then, a parametric study is presented in order to investigate the effects of the discontinuity size and location on the bending and torsional natural frequencies of laminated composite plates with various forms of discontinuities. The performed analyses demonstrate the accuracy of the proposed models to represent the free vibrations of laminated composite plates with discontinuities.

Synthesis and Generation of CuO and Mn Doped CuO Composites and its Corrosion Behaviour

Manganese doped and undoped nanocrystalline copper oxide (CuO) powder has been synthesized by co-precipitation method. The aqueous sodium hydroxide solution as precipitating agent and cetyl trimethyl ammonium bromide (CTAB) as a surfactant were used. The CuO and doped CuO samples were characterized through XRD, SEM, EDS and FTIR Spectral methods. The XRD studies revealed the crystallite size of the as prepared CuO and Mn doped CuO was in the nano range. The Hull cell experiment was conducted to optimize zinc composite plating solution parameters using electrolyte containing with and without CuO and doped CuO nano particles. Optimized plating solution was used to obtain zinc composite coating on steel material. The corrosion behavior of as generated composites on steel was investigated by Tafel and electrochemical impedance spectroscopy. The composite coated steel showed good corrosion resistance property than zinc coating.

Research on Ni-P-Carbon-Nanotube Electro-Brush Plating Composite Coating Technology

A film of Ni-P-Carbon-nanotube composite material is deposited on the surface of the metal substances by electro-brush plating. In this process, the composition of the Ni-P-Carbon-nanotube composite plating solution, the pretreatment on the carbon-nanotube and the effects on quality by the different brush plating technology conditions are investigated. The results shows that carbon-nanotube particles can be distributed uniformly in the coating by oxidizing, sensitizing and activating while the temperature of the plating solution should be controlled at 55°C, and PH value, 1.5~2.5. After the carbon-nanotube is added, the coating defects, such as the crack, the desquamation and the low bond strength, can be prevent effectively.

The effect of anisotropy on post-buckling behavior of laminated plates using semi-energy finite strip method

The effects of anisotropy (i.e. the ratio of longitudinal modulus of elasticity to transverse modulus of elasticity of a rectangular plate) on buckling and post-buckling performance of laminated plates under uniform end-shortening have been studied in this paper by implementing a Rayleigh–Ritz approach and a finite strip approach based on the concept of a rigorous post-buckling solution for composite plates and plate structures, namely the semi-energy approach. To validate the results, they are compared with those obtained from finite element method of analysis. The study of results has revealed that the buckling and post-buckling response of the laminates is significantly influenced by the changing of the anisotropy ratio.

Solutions of beam-shaped-function for analysis of composite plates with embedded delaminations

Based on beam-shaped-function, the analytical solution for composite plates with arbitrary embedded delaminations is presented. The deflection function of the delaminated plate is composed by those of beams with the corresponding loading and support conditions, which can be easily and accurately derived from the beam analysis, and the deflection amplitude is derived by the minimum potential energy principle. The closed form solutions of displacements, stresses, and energy release rate of a composite plate containing an arbitrarily embedded rectangular delamination are obtained and compared with the three-dimensional finite element results to validate the accuracy of this present method. Furthermore, the influences of delamination depth, length, central position, and modulus mismatch ratio (E1/E2) of the upper and lower sublaminate on the energy release rate are discussed.

The Manufacturing Method of Diamond Dressing Gears for the Dressing of Honing Rings

The gear honing process is a widely used process for gear finishing after heat-treated. The honing ring is profiled by diamond dressing gear, which have the profile of the workpiece to be machined and bonded a single layer of diamond particles. The paper has inroduced the traditional manufacturing methods of diamond dressing gears, positive electroplating and negative electroplating. Then put forward a new manufacturing method, Electroless nickel coating. Composition and condition of electroless composite plating solution, process steps are given. Several diamond dressing gears are made by this new method. Honing experiment testified that it is an applied method and has many advantages.

Semi-energy finite strip post-buckling analysis of laminated plates concerning the effects of mechanical coupling

In composite laminated plates the mechanical coupling is one of the significant properties which dominate the performance of a laminated plate structure in large out-of-plane deformations. Some effects of mechanical coupling on the post-buckling behavior of composite laminated plates have been studied in this paper by implementing a finite strip approach based on the concept of a rigorous post-buckling solution for composite plates and plate structures, namely the semi-energy approach, which has been originally developed by the authors of current paper. Moreover, to check the validity and soundness of presented semi-energy FSM the results obtained from developed approach are compared with those obtained from a fairly conventional and well exploited finite strip technique, namely the full-energy finite strip method as well as the obtained results from ANSYS (i.e. the general purpose finite element method software). In this paper, the post-buckling behavior of an anti-symmetric angle-ply square plate with the stacking sequence configuration as [±45]2 has been studied. Moreover, according to anti-symmetric nature of lamination in the mentioned plate there exists a mechanical coupling between in-plane membrane and out-of-plane twisting curvature; therefore, the results of this analysis have been referred as coupled solution in this paper. In order to evaluate the effects of mechanical coupling on the post-buckling performance of mentioned plates, the uncoupled solution has also been determined by precluding the coupling terms (i.e. B16, B26). The post-buckling load–end shortening and load-maximum out-of-plane deflection paths have been obtained for coupled as well as uncoupled solutions. The comparison between the obtained results by coupled and uncoupled solutions revealed markedly different behaviors due to presence of mechanical coupling in the anti-symmetric angle-ply laminates. The outcome of the paper can help structural designers have a better understanding of the effects of mechanical coupling on the post-buckling behavior of laminated composite plates at the design stage.

The effects of bend–twist coupling on the post-buckling characteristics of composite laminated plates using semi-energy finite strip approach

In composite laminated plates various mechanical properties may be attained by changing the lay-up arrangement. The bent–twist coupling is one of the significant properties which dominate the mechanical performance of a laminated plate structure in large out-of-plane deformations. The effects of bend–twist coupling on the post-buckling behavior of composite laminated plates have been studied in this paper by implementing a finite strip approach based on the concept of a rigorous post-buckling solution for composite plates and plate structures, namely the semi-energy approach. All the plates are assumed to be symmetrically balanced laminates having uniform in-plane stiffness properties. As far as the out-of-plane stiffness properties are concerned, all the properties, except for the bend–twist coupling terms which are assumed to change from one laminate to another, are the same among different laminates. The orthotropic solutions have also been determined by precluding the bend–twist coupling terms. A comprehensive set of parametric studies have been carried out to investigate the effects of bend–twist coupling terms on the post-buckling load–displacement path, post-buckling deformations and stress distribution. The comparison between the results revealed markedly different behaviors among different laminates due to the bend–twist coupling effects. The outcome of the paper can help structural designers to have a better understanding of the effects of bend–twist coupling terms on the post-buckling behavior of laminated composite plates at the design stage.

A multi‐term semi‐energy finite strip method for post‐buckling analysis of composite plates

AbstractIn this paper a finite strip approach based on the concept of a rigorous post‐buckling solution for composite plates, namely the semi‐energy approach, is presented. Moreover, in semi‐energy finite strip approach, the out‐of‐plane displacement field of the finite strip is the only displacement which is postulated by a deflected form. The postulated deflected form is substituted into von Kármán's compatibility equation which is solved exactly to obtain the corresponding forms of the mid‐plane stresses and displacements. The solution of von Kármán's compatibility equation and the postulated out‐of‐plane deflected form are then used to evaluate the potential energy of the related finite strip. Finally, by invoking the principle of minimum potential energy, the equilibrium equations of the finite strip are derived. The developed finite strip method (FSM) is applied to analyse the post‐buckling behaviour of laminated composite plates. As far as, the validity and numerical efficiency of the developed semi‐energy FSM is concerned, the results obtained from semi‐energy FSM approach are compared with those obtained from a fairly conventional and well exploited finite strip technique, namely the full‐energy finite strip method. The study of the results revealed that the developed semi‐energy FSM provides a very higher convergence and stress distribution properties in comparison with the full‐energy solution by incorporating considerably less number of degrees of freedom. This means that from the computational economy point of view, the developed semi‐energy FSM is superior to the full energy FSM. Copyright © 2006 John Wiley & Sons, Ltd.

Modelling of composite and sandwich plates by a trigonometric layerwise deformation theory and radial basis functions

In this paper we use a trigonometric layerwise deformation theory for modelling symmetric composite plates. We use a meshless discretization method based on global multiquadric radial basis functions. The results obtained are compared with solutions derived from other models and numerical techniques. The results show that the use of trigonometric layerwise deformation theory discretized with multiquadrics provides very good solutions for composite plates and excellent solutions for sandwich plates.

On the Displacement Field for Unidirectional Off-Axis Composites in 3-Point Flexure — Part 1: Analytical Approach

The displacement field of a unidirectional off-axis specimen in 3-point flexure test is obtained in a new way, by applying the Second Castigliano's theorem and the unitarial load method. The displacement field is calculated for two cases: in the first one, lift-off between specimen and fixture support occurs caused by bending-twisting coupling, and specimen is supposed to contact with the test fixture support at two diagonally opposite points. In the second case, lift-off does not occur and specimen is supposed to contact with the fixture support at four corners. The limit between two cases is established by the calculation of the critical value of the span-to-width ratio for lift-off to occur. The displacement field calculated includes shear effects and satisfies displacements compatibility and equilibrium conditions, except in the vicinity of point reactions and applied load. Neither displacement field solutions for composite plates with point boundary conditions, nor solutions based on the Second Castigliano's theorem concerning composite plates have been encountered in the literature survey.