Ph.D. Tezi Görüntüleme

      In this study, the solution of the continuous and discontinuous contact problem in two layers with different heights one of which functionally graded (FG) on a rigid plane and loaded with two flat rigid blocks was considered according to the elasticity theory. The FG layer was loaded from the upper surface by two rigid blocks (b-a) and (d-c) with external loads P and Q. In the first part, studies on contact problems were summarized. In addition, general equations for both two layer were obtained with the help of general equations of elasticity. In the second part, the problem of continuous and discontinuous contact was discussed separately. In the case of continuous contact, the problem was solved by the appropriate Gauss-Chebyshev integration by using the condition that the derivative of the vertical displacement function between the blocks and the functionally graded layer was equal to zero. In this section, contact stresses under blocks, initial separation load and distances under the layers and stresses were examined. In the problem of discontinuous contact, initial separation under the layers were discussed. In case of discontinuous contact, the unknown contact stresses under the blocks as well as the slope of the separation at the contact surface were taken as unknowns. These unknowns were obtained from the solution of the problem reduced to the system of singular integral equation by Gauss-Chebyshev integration. Thus, separation start and end points, stresses along the layer axis and openings at the interface were found. In addition problem analyzed with finite element method (FEM) using by the ANSYS Mechanical APDL program. In the last section, the results obtained from the solutions were interpreted with graphics and tables. In the comparisons of the analytical solution, the FEM solution and the studies in the literature, quite compatible results were obtained.