疲劳尺寸效应之高应力体积法研究进展
Highly Stressed Volume Approach in Size Effect Analysis of Fatigue: State of the Art
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摘要: 重大装备结构尺寸的愈趋增大及对安全运行需求的不断提升, 对其可靠性指标提出了更高要求, 推动了尺寸效应下疲劳寿命预测理论的发展。尺寸效应泛指尺寸相关因素对材料/结构疲劳强度的影响。传统疲劳设计理论通常以小尺寸材料级试验为依托, 并通过经验性尺寸系数量化尺寸效应的影响。作为常用的尺寸效应建模方法, 高应力体积法实现了不同尺寸结构间疲劳性能的精确描述和稳健传递。该文系统阐释尺寸效应下疲劳寿命评估发展史及基本分析流程, 总结高应力体积法发展现状及尺寸效应分析流程, 对比高应力体积法与临界距离、最弱链等理论的预测效果及方法优缺点, 最后, 总结、梳理其发展瓶颈并对未来发展方向作出展望。Abstract: With increasing structural size of main components and increasing demand for service safety, higher reliability index demand is imposed, promoting the development of life prediction theories considering size effect. Size effect refers to the influence of structural size on the fatigue strength. However, traditional fatigue life design theories are normally developed based on small-scale material level tests, and the size factor is then utilized for quantifying the size effect. As an effective method for size effect modelling, the highly stressed volume (HSV) approach provides accurate description and robust transfer of fatigue performance between structures with different sizes. Development history and basic analysis process of fatigue life assessment under size effect were systematically reviewed. Development status as well as the HSV-based size effect modelling framework were summarized. Predictive ability of the HSV approach was compared with the theory of critical distance and weakest link theory as well as their advantages and disadvantages. Finally, development bottleneck was summarized, and future trends were prospected.