关键词: 疲劳裂纹, 表面裂纹, 萌生与扩展, 数值模拟

Abstract:

The behavior of short cracks charges the damage process of high-temperature fatigue, and the study on short fatigue crack is of great importance. Based on experiment of 2.25Cr-1Mo material's short cracks' collective evolution behavior, a stochastic physical model was proposed for visualizing the spatial and temporal distribution of stochastic cracks and evaluating the process of fatigue damage according to the characteristics of short cracks' behavior in this paper. The model considered the influence of microstructure and the interaction of short cracks. Not only the statistic feature of short fatigue cracks but also those of single cracks can be obtained by using this model. Simulation results agreed well with those of experiments. Some features of short fatigue cracks were also obtained through the analysis of simulation results.

Key words: sho rt fatig ue cr ack, surface cra ck, initiatio n and pr o pag atio n, numerical simulatio n