Accuracy of the predicting for creep-fatigue cyclic life based on parameters in a characteristic cycle
Accuracy of the predicting for creep-fatigue cyclic life based on parameters in a characteristic cycle
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DOI：
10.1016/j.engfracmech.2021.107955
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发表时间：
2021-10
影响因子：
5.4
通讯作者：
B. Ding;W. Ren;Y. Zhong;Xiaotan Yuan;J. Peng;T. Zheng;Z. Shen;Yifeng Guo;W. Xuan;Jianbo Yu-Jia
中科院分区：
文献类型：
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作者：
B. Ding;W. Ren;Y. Zhong;Xiaotan Yuan;J. Peng;T. Zheng;Z. Shen;Yifeng Guo;W. Xuan;Jianbo Yu-Jia
本工作的目的是评价蠕变-疲劳寿命预测的特征循环预测精度，分析各种模型在拉伸应变-停留试验中的优缺点。根据定向凝固镍基高温合金DZ445在900℃下的蠕变疲劳数据，将我们提出的第一循环、10%寿命、半衰期和特征循环参数(初始快速软化和随后的轻微软化/硬化的转折点)用于线性损伤总和(LDS)和能量寿命预测模型，发现具有明确物理意义的特征循环参数具有最高的寿命预测精度。此外，还确定了LDS中疲劳和蠕变损伤的最佳临界值(蠕变-疲劳包络交点坐标)。在LDS准则中，基于时间分数、简单延性耗竭和应变-能量-密度-耗竭模型的蠕变损伤预测精度依次提高。在能量寿命模型中，基于损伤机理和频率修正的寿命预测精度高于未经修正的结果。该研究为蠕变疲劳寿命预测提供了一种准确、方便的新的参数选择方法。为实验室试验和实际构件的蠕变疲劳寿命预测提供了理论指导。
The purposes of the present work are to evaluate the prediction accuracy of characteristic cycle on creep-fatigue life prediction and to analyze the advantages and disadvantages of various models in tensile strain-dwell tests. The parameters of the first cycle, the 10% life, the half-life, and the characteristic cycle that we proposed (a turning point between the initial rapid softening and subsequent slight softening/hardening) are employed to linear-damage-summation (LDS) and energy-life prediction models based on the creep-fatigue data of directionally-solidified Nickel-based superalloy, DZ445, at 900 °C. It is found that the characteristic cycle parameters with clear physical significance have the highest life prediction accuracy. Moreover, the optimal critical value of fatigue and creep damage (the coordinate of the creep-fatigue envelope intersection) in the LDS is also determined. The prediction accuracy of creep damage based on the time-fraction, the simple ductility-exhaustion, and the strain-energy- density-exhaustion models is sequentially improved in the LDS rule. In the energy-life model, the life prediction accuracy based on damage mechanism and frequency correction is higher than the value without any correction. This investigation provides a new method of the parameter-selection for the creep-fatigue life prediction, which is accurate and convenient. It provides the theoretical-guidance for creep-fatigue life prediction in both laboratory experiment and actual components.