A simplified analysis of creep crack growth using local approach

The use of Fracture Mechanics parameters (K, J, C^*) is subjected to serious limitations when viscoplastic strain appears in a cracked structure. It is therefore one of the cases where a local approach of fracture might be the only mean to help understand the complex mechanical phenomena which influence crack growth. Using a very simple local fracture law, called sudden damage model, various closed form solutions of creep damage zone growth are proposed. With the help of a Double Cantilever Beam (DCB) model to simplify the geometry of the cracked structure, crack initiation and growth are analytically studied. Points such as creep zone size, stress redistribution or influence of local fracture criterion are discussed using closed form solutions.