Abstract:
In this thesis, analytical crack initiation criteria are evaluated in detail. Finite element method is used to determine crack initiation angles for edge cracked functionally graded materials. Minimum strain energy density (S), maximum energy release rate (G), and maximum triaxial stress (M) criteria are used in numerical analysis. Several finite element models are constructed to investigate the effect of crack length, crack angle and material non-homogeneity on crack initiation angle. Results of minimum strain energy density (S), energy release rate (G), maximum triaxial stress (M) and maximum tangential stress (MTS) criteria are compared.