航空学报 > 2023, Vol. 44 Issue (10): 427300-427300   doi: 10.7527/S1000-6893.2022.27300

基于晶体塑性理论的高-低周疲劳寿命预测统一准则

王秀锐1, 李凯尚1, 谷行行1, 张勇1, 陆体文1, 王润梓2, 张显程1()   

  1. 1.华东理工大学 教育部承压系统与安全重点实验室,上海  200237
    2.东北大学(日本) 工学研究科 断裂与可靠性研究所,仙台 9808579
  • 收稿日期:2022-04-19 修回日期:2022-05-05 接受日期:2022-06-20 出版日期:2022-06-29 发布日期:2022-06-27
  • 通讯作者: 张显程 E-mail:xczhang@ecust.edu.cn
  • 基金资助:
    国家自然科学基金(52005185)

A unified criterion for high⁃low cycle fatigue life prediction based on crystal plasticity theory

Xiurui WANG1, Kaishang LI1, Hanghang GU1, Yong ZHANG1, Tiwen LU1, Runzi WANG2, Xiancheng ZHANG1()   

  1. 1.Key Laboratory of Pressure Systems and Safety,Ministry of Education,East China University of Science and Technology,Shanghai  200237,China
    2.Fracture and Reliability Research Institute,Graduate School of Engineering,Tohoku University,Sendai 9808579,Japan
  • Received:2022-04-19 Revised:2022-05-05 Accepted:2022-06-20 Online:2022-06-29 Published:2022-06-27
  • Contact: Xiancheng ZHANG E-mail:xczhang@ecust.edu.cn
  • Supported by:
    National Natural Science Foundation of China(52005185)

摘要:

在晶体塑性有限元的框架下建立了关于镍基合金Inconel 718(IN718)从低周疲劳(LCF)到高周疲劳(HCF)的寿命预测统一准则。在介观尺度下通常借助疲劳指示因子(FIP)进行寿命预测,例如基于FIP累积能量耗散可较好地预测IN718的LCF寿命,但对于HCF寿命的预测过于非保守,从而使工程构件面临过早疲劳失效的风险。因此在累积能量耗散的基础上考虑有效弹性能,定义一个新的FIP,即有效能。假设有效能的临界值是一个与加载条件无关的常数,当每周次的有效能累加到这个临界值时材料的疲劳寿命便可被确定。基于有效能的寿命预测准则不仅可较好地预测IN718的LCF寿命,还可较好地预测IN718的HCF寿命。然而结果显示不同应变幅下的有效能临界值并不相等,且不同应变幅下的有效能临界值与每周次的有效能间成双对数线性关系。基于此对基于有效能的寿命预测准则进行进一步的修正。结果表明修正的寿命预测准则不仅对LCF和HCF寿命有较高的预测精度,且其寿命预测稳定性也有提高。

关键词: 晶体塑性, 有限元, 疲劳指示因子, 寿命预测, 统一准则

Abstract:

A life prediction unified criterion is developed for Inconel 718 (IN718) from Low Cycle Fatigue (LCF) to High Cycle Fatigue (HCF) within the crystal plasticity finite element framework. On the mesoscopic scale, the life prediction is completed with the help of Fatigue Indicator Parameter (FIP). For example, the LCF life is predicted well based on the FIP accumulated energy dissipation for IN718, while the predicted HCF life is too non-conservative, which will make the engineering components face the risk of advanced fatigue failure. Therefore, a new FIP, effective energy, is developed by the combination of effective elastic energy and accumulated energy dissipation. The critical value of effective energy is assumed to be a loading-condition-independent constant. When the effective energy per cycle is added up to the critical value, the fatigue life of the material can be determined. Not only the LCF life of IN718 but also the HCF life of IN718 is predicted well based on effective energy. However, results show that the critical values of effective energy for different strain amplitudes are not equal. And there is a double logarithmic linear relationship between the critical values of effective energy and effective energy per cycle under different strain amplitudes. Based on this, the life prediction criterion based on effective energy is modified. Results show that the modified life prediction criterion not only has higher life prediction accuracy but also has better life prediction stability for LCF and HCF life.

Key words: crystal plasticity, finite element, fatigue indicator parameter, life prediction, unified criterion

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