The Experts below are selected from a list of 16890 Experts worldwide ranked by ideXlab platform
Mehmet A Guler - One of the best experts on this subject based on the ideXlab platform.
-
a frictional receding contact plane problem between a functionally graded layer and a homogeneous substrate
International Journal of Solids and Structures, 2014Co-Authors: Shameem Usman, Mehmet A Guler, Sami ElborgiAbstract:Abstract This paper investigates the plane problem of a frictional receding contact formed between an elastic functionally graded layer and a homogeneous half space, when they are pressed against each other. The graded layer is assumed to be an isotropic nonhomogeneous medium with an exponentially varying shear modulus and a constant Poisson’s ratio. A segment of the top surface of the graded layer is subject to both normal and tangential traction while rest of the surface is devoid of traction. The entire contact zone thus formed between the layer and the homogeneous medium can transmit both normal and tangential traction. It is assumed that the contact region is under sliding contact conditions with the Coulomb’s law used to relate the tangential traction to the normal component. Employing Fourier integral transforms and applying the necessary boundary conditions, the plane elasticity equations are reduced to a singular integral equation in which the unknowns are the contact pressure and the receding contact lengths. Ensuring mechanical Equilibrium is an indispensable requirement warranted by the physics of the problem and therefore the global force and Moment Equilibrium conditions for the layer are supplemented to solve the problem. The Gauss–Chebyshev quadrature-collocation method is adopted to convert the singular integral equation to a set of overdetermined algebraic equations. This system is solved using a least squares method coupled with a novel iterative procedure to ensure that the force and Moment Equilibrium conditions are satisfied simultaneously. The main objective of this paper is to study the effect of friction coefficient and nonhomogeneity factor on the contact pressure distribution and the size of the contact region.
Sami Elborgi - One of the best experts on this subject based on the ideXlab platform.
-
a frictional receding contact plane problem between a functionally graded layer and a homogeneous substrate
International Journal of Solids and Structures, 2014Co-Authors: Shameem Usman, Mehmet A Guler, Sami ElborgiAbstract:Abstract This paper investigates the plane problem of a frictional receding contact formed between an elastic functionally graded layer and a homogeneous half space, when they are pressed against each other. The graded layer is assumed to be an isotropic nonhomogeneous medium with an exponentially varying shear modulus and a constant Poisson’s ratio. A segment of the top surface of the graded layer is subject to both normal and tangential traction while rest of the surface is devoid of traction. The entire contact zone thus formed between the layer and the homogeneous medium can transmit both normal and tangential traction. It is assumed that the contact region is under sliding contact conditions with the Coulomb’s law used to relate the tangential traction to the normal component. Employing Fourier integral transforms and applying the necessary boundary conditions, the plane elasticity equations are reduced to a singular integral equation in which the unknowns are the contact pressure and the receding contact lengths. Ensuring mechanical Equilibrium is an indispensable requirement warranted by the physics of the problem and therefore the global force and Moment Equilibrium conditions for the layer are supplemented to solve the problem. The Gauss–Chebyshev quadrature-collocation method is adopted to convert the singular integral equation to a set of overdetermined algebraic equations. This system is solved using a least squares method coupled with a novel iterative procedure to ensure that the force and Moment Equilibrium conditions are satisfied simultaneously. The main objective of this paper is to study the effect of friction coefficient and nonhomogeneity factor on the contact pressure distribution and the size of the contact region.
Vu Ngoc Pi - One of the best experts on this subject based on the ideXlab platform.
-
optimum calculation of partial transmission ratios of mechanical driven systems using a v belt and a three step bevel helical gearbox
International Conference on Engineering Research and Applications, 2018Co-Authors: Nguyen Khac Tuan, Tran Thi Phuong Thao, Le Xuan Hung, Vu Ngoc PiAbstract:This paper introduces a study on the optimum determination of partial transmission ratios of a mechanical drive system using a V-belt and a three-step bevel helical gearbox for getting the minimum height of the system. In the study, the height of the system was chosen as the objective function. Also, in the optimization problem, the design equation for pitting resistance of a gear set was investigated. Besides, equations on Moment Equilibrium condition of a mechanic system including a V-belt and a three-step bevel helical gear-box and their regular resistance condition were analyzed. From the results of the study, effective models for calculation of the partial ratios of the V-belt and a three-step bevel helical gearbox were reported. As the models are explicit, the partial ratios can be calculated accurately and simply.
-
determining optimal partial transmission ratios of mechanical driven systems using a v belt drive and a helical reducer with second step double gear sets
International Conference on Engineering Research and Applications, 2018Co-Authors: Vu Ngoc Pi, Nguyen Khac Tuan, Le Xuan Hung, Tran Thi Phuong ThaoAbstract:This paper presents a new study on the calculation of optimum gear ratios of a mechanical drive system which used a V-belt drive and a two-step helical reducer with second-step double gear-sets. In the study, the objective function of the optimization problem was the system cross section area. Besides, the design equation for pitting resistance of a gear-set was considered. In addition, the equations on the Moment Equilibrium condition of a mechanic system including a V-belt drive and a two-step helical reducer with second-step double gear-sets and their regular resistance condition were conducted. From the results of the study, the equations to determine the optimal partial ratios of the V-belt drive and two steps of the reducer were obtained. By using these equations, the optimum partial ratios can be calculated accurately in a simple way.
-
optimal determination of partial transmission ratios for four step helical gearboxes with first and third step double gear sets for minimal mass of gears
ACC'08 Proceedings of the WSEAS International Conference on Applied Computing Conference, 2008Co-Authors: Vu Ngoc PiAbstract:This paper introduces a new study on the applications of optimization and regression analysis techniques for optimal determination of partial transmission ratios of four-step helical gearboxes with first and third step double gear-sets in order to get the minimal mass of gears. In the study, based on the Moment Equilibrium condition of a mechanic system including gear units and their regular resistance condition, an optimization program for determining the partial ratios of the gearboxes is carried out. From the results of the optimization program, explicit models for calculation of the partial ratios are introduced by using regression analysis. Using these models, the calculation of the partial ratios becomes accurate and simple.
-
optimal determination of partial transmission ratios of three step helical gearboxes with first and third step double gear sets for minimal mass of gears
MATH'08 Proceedings of the American Conference on Applied Mathematics, 2008Co-Authors: Vu Ngoc PiAbstract:This paper introduces a new study on the applications of the optimization and computer techniques for optimal determination of partial ratios of three-step helical gearboxes with first and third-step double gearsets for minimal mass of gears. In the study, from the condition of the Moment Equilibrium of a mechanic system including gear units and their regular resistance condition, models for prediction of the partial ratios of the gearboxes were proposed. Especially, explicit models for determination of the partial ratios are introduced by using regression analysis technique. Using these models, the prediction of the partial ratios becomes accurate and simple.
İsa Çömez - One of the best experts on this subject based on the ideXlab platform.
-
A receding frictional contact problem between a graded layer and a homogeneous substrate pressed by a rigid punch
Mechanics of Materials, 2017Co-Authors: Sami El-borgi, İsa ÇömezAbstract:Abstract This paper considers the plane problem of a receding frictional nonlinear contact between an elastic graded layer and a homogeneous half-space when they are pressed against each other by a rigid stamp. A non-homogenous isotropic stress-strain law was used to model the graded layer. The contact region is assumed to be under sliding contact conditions with Coulombs law relating the tangential traction to the normal component. Applying Fourier integral transform and the appropriate boundary conditions, the plane elasticity equations are converted analytically into a system of singular integral equations in which the unknowns are the pressures and receding contact lengths in the two contact zones. Ensuring mechanical Equilibrium is an indispensable requirement warranted by the physics of the problem and therefore the global force and Moment Equilibrium conditions for the stamp and the layer are supplemented to solve the problem. The Gauss–Chebyshev quadrature-collocation method is used to convert the singular integral equations into a set of nonlinear equations which are solved with a newly developed iterative algorithm to yield the lengths of the receding contact zones and the associated contact pressures. The main focus of this paper is to investigate the effect of the non-homogeneity parameter of the graded layer, the friction coefficient in the contact zones and the radius of the stamp profile on the contact pressures and lengths of the receding contact zones.
Ben Leshchinsky - One of the best experts on this subject based on the ideXlab platform.
-
required unfactored strength of geosynthetics in reinforced 3d slopes
Geotextiles and Geomembranes, 2014Co-Authors: Fei Zhang, Dov Leshchinsky, Yufeng Gao, Ben LeshchinskyAbstract:Abstract The design of reinforced earth structures uses idealized two-dimensional (2D) geometry – classifying as a plane-strain analysis. This 2D idealization greatly simplifies design by ignoring stabilizing effects posed by three-dimensional (3D) characteristics. While the outcome of this 2D idealization is conservative in terms of required reinforcement strength, ignoring 3D end effects in back-calculations of experimental and field data may overestimate the contribution of the reinforcement to stability thus possibly leading to unconservative learned lessons related to design. The objective of this study is to explore 3D effects on the required strength of reinforcement in geosynthetic-reinforced earth structures (GRESs) using a modified 3D limit Equilibrium (LE) slope stability analysis. To determine the stability of GRESs, a rotational, 3D failure mechanism, derived from variational LE analysis, is applied using a log-spiral surface generalized to 3D conditions. In order to determine the long-term strength of geosynthetics required to ensure sufficient internal stability, the Moment Equilibrium approach is applied and its respective equations solved. In order to conveniently assess the end effects on the required total strength of reinforcement and the volume of failing mass considering the feasible length of potential failure, a series of design charts are presented. These charts can also be useful in forensic studies when back-calculating the in-situ mobilized strength of the geosynthetic for 3D failures. The impact of seismicity and the assumed function of forces distributed amongst the reinforcement layers were investigated to highlight their importance. To keep this study focused on 3D end effects, this study is limited to a simple 3D GRES problem; however, extending the present framework to deal with complex homogenous problems is straightforward.