Micromechanical local approach to brittle failure in bainite high resolution polycrystals: A short presentation

作者：N' Guyen C N; Barbe F^*; Osipov N; Cailletaud G; Marini B; Petry C

来源：Computational Materials Science, 2012, 64: 62-65.

DOI：10.1016/j.commatsci.2012.03.034

• Brittle failure
• Micromechanical local approach
• Polycrystals
• Microstructural barriers

The problem of determining the probability of failure in a brittle material from a micromechanical local approach has recently been addressed in few works ([1-3]), all related to bainite polycrystals at different temperatures and states of irradiation. They have separately paved the ground for a full-field modelling with high realism in terms of constitutive modelling and microstructural morphology. This work first contributes to enhance this realism by assembling the most pertinent/valuable characteristics (dislocation density based model, large deformation framework, fully controlled triaxiality conditions, explicit microstructure representation of grains and sub-grains, ... ) and by accounting for a statistically representative Volume Element; this condition indeed must be fulfilled in order to capture rare events like brittle micro-fractures which, in the stress analysis, correspond to the tails of distribution curves. The second original contribution of this work concerns the methodology for determining fracture probabilities: rather than classically - and abruptably - considering a polycrystal as broken as soon as an elementary link (grain or sub-grain) has failed, the possibility of microcrack arrest at microstructural barriers is introduced, which enables to determine the probability of polycrystal failure according to different scenarii of multiple micro-fractures.

• 出版日期2012-11
• 单位中国地震局