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论文类型：期刊论文

发表时间：2012-12-01

发表刊物：INTERNATIONAL JOURNAL OF FATIGUE

收录刊物：SCIE

卷号：45

页面范围：1-7

ISSN号：0142-1123

关键字：Short fatigue cracks; Collective evolution; High temperature; Fractal dimension; Plastic strain energy density

摘要：This paper proposes a Paris-type damage model to investigate the collective evolution of short fatigue cracks based on fractal theory. On the basis of experimentally determined images, the fractal dimensions (FDs) of rounded notched specimens' surfaces are numerically calculated by using Otsu threshold segmentation and box-counting dimension method. The results show that FDs' evolution presents "HILL" curves' characteristics. The transition period between FD rapid growth stage and FD constant stage takes place at about 30% of fatigue life. The good match between experimental results and FEM analyses reveals the model can describe collective damage process caused by all fatigue cracks. (C) 2012 Elsevier Ltd. All rights reserved.