Computational Methods for Inclined Cracks in Orthotropic Functionally Graded Materials Under Thermal Stresses

Dağ, Serkan
This article sets forth two different computational methods developed to evaluate fracture parameters for inclined cracks lying in orthotropic functionally graded materials, that are under the effect of thermal stresses. The first method is based on the J(k)-integral, whereas the second entails the use of the J(1)-integral and the asymptotic displacement fields. The procedures introduced are implemented by means of the finite element method and integrated into a general purpose finite element analysis software. Numerical results are generated for an inclined edge crack in an orthotropic functionally graded layer subjected to steady-state thermal stresses. Comparisons of the mixed-mode stress intensity factors computed by the use of the proposed methods to those calculated by the displacement correlation technique point out that both approaches lead to numerical results of high accuracy. Further results are provided in order to illustrate the influences of inclination angle, material property gradation, and crack length upon the thermal fracture parameters.


Thermal fracture analysis of orthotropic functionally graded materials using an equivalent domain integral approach
Dağ, Serkan (2006-12-01)
A new computational method based on the equivalent domain integral (EDI) is developed for mode I fracture analysis of orthotropic functionally graded materials (FGMs) subjected to thermal stresses. By using the constitutive relations of plane orthotropic thermoelasticity, generalized definition of the J-integral is converted to an equivalent domain integral to calculate the thermal stress intensity factor. In the formulation of the EDI approach, all the required thermomechanical properties are assumed to ha...
TOPAL, SERRA; Dağ, Serkan (2014-06-27)
Functionally graded materials (FGMs) are multi-phase inhomogeneous composites, possessing smooth spatial variations in certain physical properties of the constituents. Depending on the types of the constituent materials used in the processing of orthotropic FGMs, the influences of thermal and hygroscopic loadings could be rather significant. This study is directed towards developing a new computational fracture analysis technique for orthotropic FGMs that are under mixed-mode hygrothermal loading. The metho...
Consideration of spatial variation of the friction coefficient in contact mechanics analysis of laterally graded materials
Dağ, Serkan (2016-01-01)
This paper presents a new analytical approach for sliding contact analysis of laterally graded materials, which allows taking into account the spatial variation of the friction coefficient. The method is developed by considering a sliding frictional contact problem between a laterally graded elastic medium and a rigid flat punch. Governing partial differential equations entailing the displacement components are derived in accordance with the theory of plane elasticity. General solutions are determined and b...
Sliding frictional contact between a rigid punch and a laterally graded elastic medium
Dağ, Serkan; Yidirim, Bora; Ozatag, A. Cihan (2009-11-01)
Analytical and computational methods are developed for contact mechanics analysis of functionally graded materials (FGMs) that possess elastic gradation in the lateral direction. In the analytical formulation, the problem of a laterally graded half-plane in sliding frictional contact with a rigid punch of an arbitrary profile is considered. The governing partial differential equations and the boundary conditions of the problem are satisfied through the use of Fourier transformation. The problem is then redu...
Thermal stress problems ın FGMS
Akdoğan, Esra Nur; Kadıoğlu, Fevzi Suat; Department of Mechanical Engineering (2019)
In this thesis transient temperature distribution, thermal stresses and thermal stress intensity factors (TSIFs) of an infinitely long functionally graded material (FGM) strip containing periodic cracks under thermal shock are studied. Thermal shock is applied by imposing a sudden change in the boundary temperatures. Solution of the present thermoelasticity problem is considered in three successive steps. First the thermal (conduction) problem is solved and the transient temperature distribution is determin...
Citation Formats
S. Dağ and S. TOPAL, “Computational Methods for Inclined Cracks in Orthotropic Functionally Graded Materials Under Thermal Stresses,” JOURNAL OF THERMAL STRESSES, pp. 1001–1026, 2013, Accessed: 00, 2020. [Online]. Available: