Search

An exhaustive analysis of transverse bending of piezoelectric integrated laminated composite plates having uncertain material properties is being carried out in the present article. Here, for the p...

The present work addresses the feasibility of friction stir butt welding of dissimilar Al6063 to polypropylene for cylindrical and threaded tool pin profile at different tool positions like tool offsetting and slotted edge–based base plate design as bridle joint to improve the weld quality. The new slotted edge–based design using threaded tool pin profile was found to be highly efficient. This work was further extended with the interaction effect of tool rotational speed and traverse speed. The major objective was to investigate the variation of axial force and torque due to the parametric variation, especially to find the correlation with weld quality characteristics. The mean and standard deviation of axial force and torque indicated the formability and material mixing capability during welding which in turn found to be highly correlated to weld bead uniformity. The joint behavior due to tensile load and bonding mechanism in weld stirred zone have been studied using stress-strain diagram and scanning electron micrographs, respectively. The weld joint interface was found to be the weakest zone rather than weld stirred zone due to the presence of carbon reach phases as per micro-hardness variation through the weld centerline along with energy dispersive spectroscopy analysis. The maximum joint efficiency was found to be 23.33% at 700-rpm tool rotation and traverse speed of 30 mm/min using threaded pin in slotted edge–based design.

In the current work, a higher order non-polynomial theory based upon nonlinear distribution of transverse shear stresses along the plate thickness is employed to apprehend the geometrically nonline...

In this article, a profile modification approach is adopted to design a spur gear set for minimization of contact stress and optimization of weight. An altering tooth sum method is used to reduce the hertzian contact stress along the path of contact. Three case studies are performed for a spur gear set with specific center distance and tooth sum of 90 (+5). A multi-objective optimization problem is formulated with contact stresses along path of contact and weight of gear set as design objectives. This nonlinear constrained optimization problem has been addressed by mean of the particle swarm optimization algorithm. Six design variables related to gear geometry and material property are used in this optimization, and all the constraints are satisfied at the optimal solution. Gear and pinion surface temperatures are below flash temperature, indicating protection against scoring wear. A higher value of AGMA scoring index is achieved in this optimum design approach. Specifically, a lighter gear with less contact stress and adequate scoring resistance is reported in this study. Promising results in terms of objective function values and computational time (cpu time) are observed. Furthermore, a CAD model is developed by means of optimized design parameters so as to check the geometric interference and practical feasibility of the design.

In this article, a profile modification approach is adopted for the design of a spur gear set to minimize the contact stress and optimize the weight. An altered tooth sum method is used to reduce the hertizian contact stress along the path of contact. Four case studies are performed for the spur gear set with specific center distance and tooth sum of 90 (±5). A multi-objective optimization problem is formulated with contact stresses along path of contact and weight of gear set as the design objectives. This nonlinear-constrained optimization problem has been addressed by mean of the particle swarm optimization algorithm. Six design variables related to gear geometry and material property are used in this optimization and all the imposed constraints are satisfied at the optimal solution. Gear and pinion surface temperatures are below flash temperature, indicating protection against scoring wear. Specifically, a lighter gear with less contact stress and adequate scoring resistance is reported in this study. Furthermore, a CAD model is developed by means of optimized design parameters so as to check the geometric interference and practical feasibility of the design.

In this paper, a nonlinear analysis for large amplitude free vibration of laminated composite plates is developed using higher-order shear deformation theory. The effect of all higher-order terms arising from nonlinear strain-displacement relations are included in the formulation and present plate theory exhibits traction-free surface of the laminated plate in von-Karman sense. A finite element procedure considering a C° continuous isoparametric nine-node rectangular element is implemented for nonlinear model. The accuracy of the theory is validated with some available theory for different aspect ratio, modular ratio, number of layers, ply orientations, etc. through some numerical examples.

This study intends to model the effect of porosity type defect and analyze the consequences of porosity on the buckling characteristic of various types of FGM sandwich combinations. Here, we consider four types of FGM sandwich combinations considering the multiple arrangements of the constituent layers (i.e., two face sheets and a core). Further, the combinations of all kinds of sandwiches are considered in such a way that there is no material discontinuity or jump. The porosity defects are modeled in this work as the criteria of stiffness reduction and incorporated in the rule of mixture. Finally, results are calculated by considering two types of porosity distribution, evenly and unevenly, while modeling the FGM plate. The buckling response of FGM sandwich plates has been analyzed under a nonuniform in-plane edge load. The application of nonuniform in-plane loads causes in-plane stresses to be nonlinear. Hence, in-plane stresses need to be calculated apriori for the buckling study of the FGM plate under nonuniform load. Further, the effects of various parameters like porosity contents, sandwich combinations, aspect ratio, thickness ratio, boundary conditions on buckling load of FGM plate have been studied in this paper.

The effect of uncertainty in material properties on the transverse bending of laminated composite plate is investigated. The transverse shear and large rotations have been included in the system equation in the framework of higher order shear deformation theory. The analysis uses Green–Lagrange nonlinear strain displacement equations to model geometric nonlinearity. The stochastic finite element analysis is performed using a direct iteration approach to handle deterministic geometric nonlinearity and perturbation approach to handle the randomness in the material properties. Mean and variance of the transverse deflection have been obtained by employing a C0 isoparametric nonlinear finite element model.

This article addresses the buckling and post-buckling stochastic analysis of a laminated composite plate having random system properties. The transverse shear effects have been included in the system equation in the framework of higher order shear deformation theory. The analysis uses Green Lagrange nonlinear strain displacement equations to model geometric nonlinearity. Direct iteration approach is used to handle deterministic geometric nonlinearity and perturbation approach is presented to handle the randomness in the system properties. Mean and variance of the random buckling and post-buckling strength have been obtained by employing a C 0 isoparametric nonlinear finite element model. Comparisons with the published results show the accuracy of the proposed probabilistic procedure. Results covering various features are presented for a laminated composite plate with different boundary conditions.

This paper addresses the buckling and post-buckling of laminated composite plates using higher order shear deformation theory associated with Green–Lagrange non-linear strain–displacement relationships. All higher order terms arising from nonlinear strain–displacement relations are included in the formulation. The present plate theory satisfies zero transverse shear strain conditions at the top and bottom surfaces of the plate in von Karman sense. A C0 isoparametric finite element is developed for the present nonlinear model.

In this work, a transverse bending of shear deformable laminated composite plates in Green–Lagrange sense accounting for the transverse shear and large rotations are presented. Governing equations are developed in the framework of higher order shear deformation theory. All higher order terms arising from nonlinear strain–displacement relations are included in the formulation. The present plate theory satisfies zero transverse shear strains conditions at the top and bottom surfaces of the plate in von-Karman sense. A C0 isoparametric finite element is developed for the present nonlinear model. Numerical results for the laminated composite plates of orthotropic materials with different system parameters and boundary conditions are found out. The results are also compared with those available in the literature. Some new results with different parameters are also presented.

This article addresses the non-linear free vibration stochastic characteristic of a laminated composite plate having random material properties. The transverse shear effects have been included in the system equation in the frame work of higher-order shear deformation theory. The analysis uses Green—Lagrange non-linear strain—displacement relationship to model geometric non-linearity. Direct iteration approach is used to handle deterministic system non-linearity and perturbation approach is presented to handle the randomness in the system properties. Mean and variance of the random natural frequencies have been obtained by employing a C0isoparametric non-linear 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.

This paper addresses the nonlinear free vibration characteristic of laminated composite plate with embedded and/or surface bonded piezoelectric layer. Nonlinear governing equations are derived in Green-Lagrange sense in the framework of a higher order shear deformation theory. All higher order terms arising from nonlinear strain-displacement relations are included in mathematical formulation. The present plate theory satisfies zero transverse shear strains conditions at the top and bottom surfaces of the plate in von-Karman sense. A C^0 isoparametric finite element is proposed for the present nonlinear model. Comparisons of the present results with those obtained by exact approach show the accuracy and necessity of the model especially for the structures undergoing large deformations. Some new examples covering various features are presented to bring out the different aspects of the model. The results would be useful for the designers.

The present study is concerned with the stochastic linear free vibration study of laminated composite plate embedded with piezoelectric layers with random material properties. The system equations are derived using higher order shear deformation theory. The lamina material properties of the laminate are modeled as basic random variables for accurate prediction of the system behavior. A C0 finite element is used for spatial descretization of the laminate. First order Taylor series based mean centered perturbation technique in conjunction with finite element method is outlined for the problem. The outlined probabilistic approach is used to obtain typical numerical results, i.e., the mean and standard deviation of natural frequency. Different combinations of simply supported, clamped and free boundary conditions are considered. The effect of side to thickness ratio, aspect ratio, lamination scheme on scattering of natural frequency is studied. The results are compared with those available in literature and an independent Monte Carlo simulation.

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 C0 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.