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- MakaleYayıncıda açık erişim2024Scopus SJRQ1Multi-method examination of contact mechanics in orthotropic layers under gravity
Öner, Erdal; Uzun Yaylacı, Ecren; Yaylacı, Murat
Analyzing the behavior of intelligent unconventional materials under diverse contact scenarios, in comparison to conventional materials, is a critical step in the initial design of engineering systems. This paper presents the development of analytical and numerical approaches for analyzing contact mechanics in a system comprising an orthotropic layer resting on a rigid foundation. Parametric analyses include the consideration of cylindrical and flat punch profiles. Analytical formulation utilizes integral transform methods to convert planar elasticity equations into a Cauchy-type singular integral equation of the second kind. A detailed description of the solution technique for the integral equation is provided, encompassing both the analytical formulation and the required discretization for obtaining the solution. Subsequently, a finite element approach (FEA) is employed to approximate contact bodies using a collection of finite elements, while contact boundaries are approximated by utilizing a set of polygons. Alternatively, the problem is addressed using the Multilayer Perceptron approach, a form of artificial neural network frequently applied in diverse machine learning applications, including scenarios involving contact problems. Finally, the resolution to the problem is achieved by employing the multilayer perceptron (MLP) method. The study yields determinations of contact stresses under the punch, the critical separation load resulting in the detachment of the orthotropic layer from the rigid foundation, and the corresponding separation distance. This analysis considers a range of dimensionless parameters and explored the behavior of diverse orthotropic materials. Comparisons between the results of the analytical method and computations from FEA and MLP reveal the exceptional accuracy attained by all three approaches. As the pioneer study employing three distinct approaches to examine continuous contact mechanics within an orthotropic layer under the influence of gravity, this research constitutes a valuable point of reference for upcoming scholars in the field.
AtıfScopus50WoS53OpenAlex44
İncele - Yüksek Lisans TeziAçık Erişim2023İzotrop yarım düzleme oturan ortotrop tabakanın sürekli temas problemi
Mine Gül Oktay
Temas mekaniği, güvenli ve enerji tasarruflu tasarımların inşası için vazgeçilmez olan mühendislik bilimlerinin temel disiplinlerindendir ve geniş teorik, sayısal ve deneysel araştırma alanını kapsamaktadır. Bu özelliğiyle mekaniğin önemli bir dalıdır ve halen de bu önemini sürdürmektedir. Temas mekaniği özellikle konvansiyonel olarak dökme malzemelerden imal edilen tribolojik ve yük aktarma düzeneklerinde öne çıkmaktadır. Mekanikte temas problemlerinin incelenmesini, varyasyonel eşitsizliklerin formülasyonu ve çözümü ile ilişkilendirmek mümkündür. Temas mekaniği konusu, son yıllarda mekanik ve uygulamalı matematik bilimlerinde yeni ve ilginç alanların gelişmesine önemli derecede katkı sağlamıştır. Debriyajlar, frenler, yol kaplamaları, lastikler, bilyalı rulmanlar, fren diskleri, menteşeler, demiryolu balastları, temeller gibi sayısız uygulama temas problemlerinin ilgi alanına girmektedir. Bu çalışmada izotrop yarım düzlem üzerine oturan ortotrop tabakanın sürekli temasına ilişkin problem incelenmiştir. Çözümde sadece ortotrop tabakanın kütle kuvveti hesaba katılmıştır. Ortotrop tabaka rijit bir panç vasıtasıyla yüklenmiştir. Tüm yüzeylerin sürtünmesiz olduğu varsayılmıştır. Çalışma sonucunda çeşitli boyutsuz parametrelere ve ortotrop malzeme türlerine bağlı olarak temas uzunluğu, temas gerilmesi, kritik ayrılma uzaklığı ve kritik ayrılma yükü boyutsuz olarak elde edilmiştir.
- MakaleAçık Erişim2023Scopus SJRQ3A STUDY ON THE CONTACT PROBLEM OF A LAYER CONSISTING OF FUNCTIONALLY GRADED MATERIAL (FGM) IN THE PRESENCE OF BODY FORCE
Adiyaman, Gökhan; Öner, Erdal; Yaylaci, Murat; Birinci, Ahmet
One of the most important components of the early design process for layered systems is gaining a knowledge of the behavior of materials under varied contact situations. Functionally graded materials (FGMs) have grown in popularity in layered systems as a result of their numerous benefits, such as permitting the reduction of local stress concentrations and thermal stresses often experienced in traditional composites. This paper suggests an analytical approach to solving the continuous and discontinuous contact problems of a functionally graded (FG) layer subjected to a distributed load. Elasticity theory and integral transform methods provide the basis of the aforementioned analytical approach. The FG layer rests on a half-plane that is homogeneous, and there is no adhesion or bonding at the contact surface. For this problem, we assume an exponentially varying shear modulus and mass density in the FG layer. In the solution, the body force of the FG layer is considered. The problem is solved analytically by applying boundary conditions for both continuous and discontinuous contact cases. The presented results show the effects of load factor, amplitude of distributed load, inhomogeneity parameters, and interface material property mismatch on contact stress distributions, initial separation load (critical load), initial separation distance, starting and end point of separation, and separation interval.
AtıfScopus39WoS40OpenAlex30İncele - MakaleYalnız künye2020Scopus SJRQ2Examination of analytical and finite element solutions regarding contact of a functionally graded layer
Yaylacı, Murat; Adıyaman, Gökhan; Öner, Erdal; Birinci, Ahmet
In this study, the continuous and discontinuous contact problems of functionally graded (FG) layer resting on a rigid foundation were considered. The top of the FG layer was loaded by a distributed load. It was assumed that the shear modulus and the density of the layer varied according to exponential functions along the depth whereas the the Poisson ratio remained constant. The problem first was solved analytically and the results were verified with the ones obtained from finite element (FE) solution. In analytical solution, the stress and displacement components for FG layer were obtained by the help of Fourier integral transform. Critical load expression and integral equation for continuous and discontinuous contact, respectively, using corresponding boundary conditions in each case. The finite element solution of the problem was carried out using ANSYS software program. In continuous contact case, initial separation distance and contact stresses along the contact surface between the FG layer and the rigid foundation were examined. Separation distances and contact stresses were obtained in case of discontinuous contact. The effect of material properties and loading were investigated using both analytical and FE solutions. It was shown that obtained results were compatible with each other.
AtıfScopus71WoS72OpenAlex22İncele - MakaleAçık Erişim2015Scopus SJRQ2Analysis of continuous and discontinuous cases of a contact problem using analytical method and FEM
Birinci, Ahmet; Adıyaman, Gökhan; Yaylacı, Murat; Öner, Erdal
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 analytic results are verified by comparison with finite element results. Finally, conclusions are presented.
AtıfScopus38WoS39OpenAlex36İncele - MakaleYayıncıda açık erişim2014Scopus SJRQ2Continuous contact problem for two elastic layers resting on an elastic half-infinite plane
Öner, Erdal; Birinci, Ahmet
The continuous contact problem for two elastic layers resting on an elastic half-infinite plane and loaded by means of a rigid stamp is presented. The elastic layers have different heights and elastic constants. An external load is applied to the upper elastic layer by means of a rigid stamp. The problem is solved under the assumptions that all surfaces are frictionless, body forces of elastic layers are taken into account, and only compressive normal tractions can be transmitted through the interfaces. General expressions of stresses and displacements are obtained by using the fundamental equations of the theory of elasticity and the integral transform technique. Substituting the stress and the displacement expressions into the boundary conditions, the problem is reduced to a singular integral equation, in which the function of contact stresses under the rigid stamp is unknown. The integral equation is solved numerically by making use of the appropriate Gauss-Chebyshev integration formula for circular and rectangular stamp profiles. The contact stresses under the rigid stamp, contact areas, initial separation loads, and initial separation distances between the two elastic layers and the lower-layer elastic half-infinite plane are obtained numerically for various dimensionless quantities and shown in graphics and tables.
AtıfScopus24WoS25OpenAlex26İncele