韩庆华^1,2, 王培鹏¹, 芦燕^1,2
AuthorsHTML:韩庆华^1,2, 王培鹏¹, 芦燕^1,2
AuthorsListE:Han Qinghua^1,2, Wang Peipeng¹, Lu Yan^1,2
AuthorsHTMLE:Han Qinghua^1,2, Wang Peipeng¹, Lu Yan^1,2
Unit:1. 天津大学建筑工程学院，天津 300072；2. 滨海土木工程结构与安全教育部重点实验室(天津大学)，天津 300072
Unit_EngLish:1．School of Civil Engineering, Tianjin University, Tianjin 300072, China
2．Key Laboratory of Coast Civil Structure Safety of China Ministry of Education(Tianjin University), Tianjin 300072, China
Abstract_Chinese:实际工程结构往往处于复杂的多向受力状态, 在循环荷载下其薄弱点发生的疲劳断裂多属于多轴疲劳失效模式．目前疲劳寿命预测方法多集中于单轴疲劳理论, 忽略了多轴疲劳问题的现实性和复杂性．首先介绍了多轴疲劳的概念和特点, 回顾了多轴低周疲劳寿命预测方法, 针对基于临界面准则的疲劳预测方法进行了总结归纳, 对比了各模型的适用范围和优缺点．研究了多轴非比例路径下剪应变幅的变化情况, 考虑了其旋转造成的全平面疲劳损伤, 提出了一种新的非比例路径因子反映剪应变幅数值和方向的变化对疲劳寿命的影响, 并将该系数引入Fatemi & Socie模型(FS模型)进行修正．通过理论值与试验值对比, 发现改进后的FS模型预测精度有所提高．
Abstract_English:Engineering structures are always subjected to the complex multi-directional loads，and the multiaxial fatigue failure mode occurs in the weak of the structures. Previous research of fatigue life prediction focuses on uniaxial fatigue，ignoring the outness and complexity of multiaxial fatigue problems. In this study，the concept and characteristics of multiaxial fatigue were firstly introduced，and low-cycle fatigue life prediction methods were reviewed. The prediction methods based on critical plane criterion were also summarized in detail，with further analysis of the application range and features. Then a new non-proportional path factor was proposed based on variation of shear strain amplitude which produces fatigue damage in every direction subjected to non-proportional loading paths. It could reflect the influence of value and direction change on multiaxial low-cycle fatigue life. The Fatemi & Socie model(FS model)was modified by introducing the new path factor into fatigue parameter. It is found that the fatigue life prediction by the modified FS model agrees well with the experimental results.
Keyword_Chinese:多轴疲劳; 寿命预测; 临界面准则; 非比例加载路径; 路径因子
Keywords_English:multiaxial fatigue; life prediction; critical plane criterion; non-proportional loading path; path factor

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