Finite element analysis on stable and unstable crack growth using singular crack tip elements was carried out for the generation and application-phase analyses. In the generation-phase analysis, relation of δ (crack mouth opening displacement) and Δa(amount of crack growth) obtained from experiment of side-grooved three point bend specimens was input and various fracture parameters proposed were investigated as the crack grows. In the application-phase analysis fracture parameter, (COD)c was used as input and critical crack tip nodal force, Fc was used to control crack growth and P-Δa or δ-Δa etc. was to be determined, and the possibility of making accurate predictions for stable and unstable crack growth was demonstrated using only the value of (COD)c. An analysis of unstable crack growth by tearing modulus based on COD resistance curve and J resistance curve was mainly performed.
