Öner, Erdal; Artar, Pınar Tuğçe

Contact mechanics has played a central role in engineering progressing from early practices in ancient civilizations to the pioneering experimental studies of early scientists and more recently to advanced computational approaches. In modern research, functionally graded materials have gained increasing attention as their continuously varying properties enable the tailoring of stress fields, improvement of resistance to thermal and mechanical loads, and enhancement of the performance and reliability of layered systems.This study addresses the continuous contact problem of a two-layered medium composed of a functionally graded orthotropic layer (FGOL) placed over a functionally graded isotropic layer (FGIL). A rigid cylindrical punch applies a static concentrated load on the FGOL, while the lower surface of the FGIL is bonded to a rigid foundation. The layers are assumed to be unbonded at their interface, and frictionless contact conditions are imposed. To capture the effect of anisotropy, actual orthotropic materials are employed in the FGOL. An exponential through-thickness variation is adopted for the FGOL stiffness coefficients and density, and for the FGIL shear modulus and density. Under plane strain conditions, the contact formulation is reduced to a singular integral equation by applying the relevant boundary conditions. The equation is solved numerically using Gauss–Chebyshev integration techniques. The results provide detailed evaluations of contact lengths, stress distributions, critical load factors, and initial separation points as functions of selected nondimensionalized parameters and different orthotropic material choices, thereby contributing to a deeper understanding of the mechanics of graded layered systems.

AtıfScopus1·WoS1·OpenAlex1

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Yaylacı, Murat; Öner, Erdal; Adıyaman, Gökhan; Öztürk, Şevval; Uzun Yaylacı, Ecren; Birinci, Ahmet

Contact mechanics analysis is crucial because such problems often arise in engineering practice. When examining contact mechanics, the material property of the contacting components is a crucially significant aspect. It is more complex to solve the contact mechanics of systems that are composed of materials that do not have a homogenous structure compared to materials that have homogeneous qualities throughout. While many studies on contact problems with homogeneous materials exist, those involving non-homogeneous materials are scarce in the literature. As material technology improves fast, there will be a greater need to solve such problems. In this respect, analytical and finite element method (FEM) solutions of the continuous and discontinuous contact problems of a functionally graded (FG) layer are carried out in this article. The FG layer in the problem rests on a rigid foundation and is pressed with a rigid punch. From the solutions, the contact length, contact stress, initial separation distance, and beginning and ending points of separation were determined, and the results were compared. It has been concluded that the FEM findings are consistent with the analytical results to a satisfactory degree. This study analyzes contact problem using different approaches and accounts for the influence of body force in a contact geometry that has yet to be reported.

AtıfScopus79·WoS83·OpenAlex68

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