Ahmet Birinci

Comparison between Analytical and ANSYS Calculations for a Receding Contact Problem

AbstractThis paper considers a receding contact problem for two elastic layers (with different elastic constants and heights) supported by two elastic quarter planes. The lower layer is supported by two elastic quarter planes, and the upper elastic layer is subjected to a symmetrical distributed load whose length is 2a on its top surface. It is assumed that contact between all surfaces is frictionless, and the effect of gravity force is neglected. First, the problem is formulated and solved using the theory of elasticity and integral transform technique. Using the integral transform technique and boundary conditions of the problem, the problem is reduced to a system of singular integral equations in which contact pressures and contact areas are unknown. The system of singular integral equations is solved numerically by using the Gauss-Jacobi integration formulation. Second, the receding contact problem has been developed based on the FEM ANSYS software. Two-dimensional analysis of the problem is carried o...

Axisymmetric crack problem of a thick-walled Cylinder with cladding

The paper considers the elastostatic axisymmetric problem for a long thick-walled cylinder containing an axisymmetric circumferential internal or edge crack with cladding. The cladding is assumed to be bonded to inner wall of the hollow cylinder. Using the standard transform technique, the problem is formulated in terms of an integral equation of the first kind which has a generalized Cauchy kernel as the dominant part. The integral equation is solved numerically by using appropriate quadrature formulas. The related stress-intensity factors are calculated for the hollow cylinder with cladding under axial load. The influence of the geometrical configuration and the cladding on the stress-intensity factors is shown graphically.

Analysis of Continuous and Discontinuous Cases of a Contact Problem Using Analytical Method and FEM

In this paper, continuous and discontinuous cases of a contact problem for two elastic layers supported by a Winkler foundation are analyzed using both analytical method and finite element method. In the analyses, it is assumed that all surfaces are frictionless, and only compressive normal tractions can be transmitted through the contact areas. Moreover, body forces are taken into consideration only for layers. Firstly, the problem is solved analytically using theory of elasticity and integral transform techniques. Then, the finite element analysis of the problem is carried out using ANSYS software program. Initial separation distances between layers for continuous contact case and the size of the separation areas for discontinuous contact case are obtained for various dimensionless quantities using both solutions. In addition, the normalized contact pressure distributions are calculated for both cases. The analytical results are verified by comparison with finite element results. Finally, conclusions are presented.

Partial closure of a crack located in an infinite elastic layer

Abstract The elastostatic plane problem of an infinite elastic layer with a crack parallel to its surfaces loaded by a transverse pair of compressive concentrated forces P and a pair of uniform compressive stress p 0 along the crack surface is considered. It is assumed that the effect of gravity force is neglected. The value of initial load factor Q c for the initial closure of the crack face is investigated and the closure length a extended while the load factor Q increases. The partial closure problem is solved assuming that the stress-intensity factor vanishes at the end point of the closure portion. The problem is formulated in terms of a singular integral equation for the derivative of the crack surface displacement. Numerical results for the stress-intensity factor, the closure (contact) length and the load factor are given for various dimensionless quantities.