Fatigue crack growth analysis models for functionally graded materials

Dağ, Serkan
The objective of this study is to develop crack growth analysis methods for functionally graded materials (FGMs) subjected to mode I cyclic loading. The study presents finite elements based computational procedures for both two and three dimensional problems to examine fatigue crack growth in functionally graded materials. Developed methods allow the computation of crack length and generation of crack front profile for a graded medium subjected to fluctuating stresses. The results presented for an elliptical crack embedded in a functionally graded medium, illustrate the competing effects of ellipse aspect ratio and material property gradation on the fatigue crack growth behavior.
9th International Conference on Multiscale and Functionally Graded Materials


Fatigue crack growth analysis models for funcionally graded materials
Sabuncuoğlu, Barış; Dağ, Serkan; Department of Mechanical Engineering (2006)
The objective of this study is to develop crack growth analysis methods for functionally graded materials under mode I cyclic loading by using finite element technique. The study starts with the analysis of test specimens which are given in ASTM standard E399. The material properties of specimens are assumed to be changing along the thickness direction according to a presumed variation function used for the modeling of functionally graded materials. The results of the study reveal the influence of different...
Computational Methods for Inclined Cracks in Orthotropic Functionally Graded Materials Under Thermal Stresses
Dağ, Serkan; TOPAL, SERRA (2013-10-03)
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 softw...
Thermal stress intensity factor evaluation for inclined cracks in functionally graded materials using Jk-integral method
Demirçivi, Bengi; Dağ, Serkan; Department of Mechanical Engineering (2006)
The main objective of this study is to evaluate mixed mode stress intensity factors for inclined embedded cracks in functionally graded materials. Fracture analysis of inclined cracks requires the calculation of both Mode I and Mode II stress intensity factors ( I K , II K ). In this study, k J -integral is used to calculate I K and II K . Equivalent domain integral approach is utilized to evaluate the k J - integral around the crack tip. The present study aims at developing a finite element model to study ...
Mixed mode fatigue crack growth path and life prediction under variable amplitude loading through extended finite element method
Dirik, Haydar; Yalçınkaya, Tuncay; Department of Aerospace Engineering (2017)
The main purpose of this study is to predict the crack growth path trajectories and fatigue crack growth (FCG) life under variable amplitude loading (VAL) by using Extended Finite Element Method (XFEM). For this purpose a computational algo- rithm is developed in Fortran which interacts with a commercial finite element soft- ware (Abaqus) and automatically propagates cracks which is initially modelled as stationary crack. Nasgro FCG equation is used for FCG life calculation which has a great accuracy among t...
Analytical Solution of a Crack Problem in a Radially Graded FGM
Cetin, Suat; Kadıoğlu, Fevzi Suat (2008-09-25)
The objective of this study is to determine stress intensity factors (SIFs) for a crack in a functionally graded layer bonded to a homogeneous substrate. Functionally graded coating contains an edge crack perpendicular to the interface. It is assumed that plane strain conditions prevail and the crack is subjected to mode I loading. By introducing an elastic foundation underneath the homogeneous layer, the plane strain problem under consideration is used as an approximate model for an FGM coating with radial...
Citation Formats
S. Dağ and B. YILDIRIM, “Fatigue crack growth analysis models for functionally graded materials,” Oahu, HI, 2006, vol. 973, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52865.