# A surface crack in a graded coating subjected to sliding frictional contact

2012-01-01
Dağ, Serkan
GÜLER, MEHMET ALİ
Gulgec, Mufit
This article presents an analytical method developed to conduct fracture analysis of functionally graded coatings that are under the effect of contact stresses. The geometric model considered comprises a functionally graded coating, which possesses a surface crack and is perfectly bonded to a homogeneous half-plane. A two-step solution procedure is put forward in which the contact and crack problems are treated separately. First, the graded coating is assumed to be in sliding frictional contact with a rigid flat punch and the contact stresses are computed. These stresses are then used as inputs for the crack problem and the mode I and II stress intensity factors are evaluated. Governing partial differential equations for the contact and crack problems are derived by using the theory of plane elasticity and solved by utilizing Fourier transformation techniques. The derivations lead to a single singular integral equation in the case of the contact problem, and two uncoupled singular integral equations in the case of the crack problem. An expansion-collocation approach is adopted for the numerical solutions of the integral equations. Comparisons of the results generated for the contact and crack problems to those available in the literature demonstrate the high levels of accuracy attained by the proposed solution techniques. Further numerical results are presented so as to illustrate the influences of material nonhomogeneity and coefficient of friction on the contact stresses and the mode I and II stress intensity factors.
ENGINEERING FRACTURE MECHANICS

# Suggestions

 Plane strain analytical solutions for a functionally graded elastic-plastic pressurized tube Eraslan, Ahmet Nedim (Elsevier BV, 2006-09-01) Plane strain analytical solutions to functionally graded elastic and elastic-plastic pressurized tube problems are obtained in the framework of small deformation theory. The modulus of elasticity and the uniaxial yield limit of the tube material are assumed to vary radially according to two parametric parabolic forms. The analytical plastic model is based on Tresca's yield criterion, its associated flow rule and ideally plastic material behaviour. Elastic, partially plastic and fully plastic stress states a...
 Prediction of forming limit curve at fracture for sheet metal using new ductile fracture criterion Dizaji, Shahram Abbasnejad; Darendeliler, Haluk; KAFTANOĞLU, BİLGİN (Elsevier BV, 2018-05-01) The application of ductile fracture criteria (DFCs) in numerical analysis of sheet metal forming processes can lead to the accurate determination of the fracture initiation. In this study, a new uncoupled ductile fracture criterion (DFC) has been developed which considers the effects of material parameters on the forming limit curves (FLCs) and can be easily implemented in the finite element codes. Two different constitutive models have been employed with the new DFC in order to evaluate the results obtaine...
 Impact essential work of fracture toughness of ABS/polyamide-6 blends compatibilized with olefin based copolymers Ozkoc, Guralp; Bayram, Göknur; Bayramli, Erdal (Springer Science and Business Media LLC, 2008-04-01) The impact fracture toughness of acrylonitrile-styrene-butadiene/polyamide-6 (ABS/PA6) blends compatibilized with 5% by weight carbon monoxide modified ethylene-n butyl acrylate-maleic anhydride (EnBACO-MAH) or ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) copolymers were examined as a function of blend ratio by standard Charpy tests, Essential Work of Fracture (EWF) Methodology and fracture surface morphologies. The samples were first processed in twin-screw extruder and they were subsequently i...
 Excessive damage increase in dual phase steels under high strain rates and temperatures Cobanoglu, Merve; Ertan, Rasim K.; Şimşir, Caner; Efe, Mert (SAGE Publications, 2020-09-01) Damage formation in dual phase steels is a complex process and it may be sensitive to the deformation conditions and mechanisms. In this study, the damage parameter is measured and compared under quasi-static and industrial forming conditions (temperatures: 25 vs 200, 300 degrees C and strain rates: 10(-3)vs 10 s(-1)) for DP590 and DP800 steels. Resonance frequency and ultrasonic sound velocity techniques are utilized for the measurements to test the effectiveness and validity of each technique. At a given ...
 Assessing the Effects of Mechanical Preventive Measures on Alkali-Silica Reaction Expansion with Accelerated Mortar Bar Test Musaoglu, Orhan; TURANLI, LUTFULLAH; Sarıtaş, Afşin (ASTM International, 2014-11-01) This paper presents a modification to the apparatus of the mortar bar test of ASTM C490 in order to assess and compare the influence of mechanical preventive measures in reducing alkali-silica reaction (ASR) expansion in concrete with respect to the traditional measures. For this purpose, reinforced mortar specimens with or without pre-stressing force applied were examined and the effects of the reinforcement ratio and pre-stressing force on ASR-induced expansion and cracking were studied through the accele...
Citation Formats
S. Dağ, M. A. GÜLER, and M. Gulgec, “A surface crack in a graded coating subjected to sliding frictional contact,” ENGINEERING FRACTURE MECHANICS, pp. 72–91, 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48437.