中国机械工程

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镁合金低周疲劳寿命预测模型探讨

陈凌1,2;张贤明1;刘飞2;欧阳平1;贾艳艳3   

  1. 1.重庆工商大学废油资源化技术与装备工程研究中心,重庆,400067
    2.重庆大学机械工程博士后科研流动站,重庆,400044
    3. 重庆工商大学制造装备机构设计与控制重庆市重点实验室,重庆,400067
  • 出版日期:2017-03-10 发布日期:2017-03-03
  • 基金资助:
    中国博士后科学基金资助项目(2015M582523);
    重庆市博士后科研特别资助项目(Xm2016061);
    重庆市教委科学技术研究项目(KJ1500624);
    重庆工商大学科研启动经费资助项目(2014-56-10)

Discussion of Low Cycle Fatigue Life Prediction Models for Magnesium Alloys

CHEN Ling1, 2;ZHANG Xianming1;LIU Fei2;OUYANG Ping1;JIA Yanyan3   

  1. 1.Engineering Research Center for Waste Oil Recovery Technology and Equipment, Chongqing Technology and Business University, Chongqing,400067
    2.Mobile Post-doctoral Research Station of Mechanical Engineering, Chongqing University, Chongqing, 400044
    3.Chongqing Key Laboratory of Manufacturing Equipment Mechanism Design and Control, Chongqing Technology and Business University, Chongqing, 400067
  • Online:2017-03-10 Published:2017-03-03

摘要: 通过铸造镁合金AZ91D和变形镁合金AZ31B室温环境下应力控制的低周疲劳试验,采用Basquin模型、SWT模型、应变能-寿命模型等模型进行了镁合金低周疲劳的寿命预测。在此基础上,基于连续介质损伤力学的不可逆热力学理论,将镁合金的低周疲劳损伤视为一个不可逆的耗散过程,用熵来反映系统的耗散过程,并以每一次循环的平均应变增量来反映平均应力对材料的影响,提出了一种新的镁合金低周疲劳寿命预测模型。用该模型进行了镁合金的低周疲劳寿命预测,预测结果与实测结果符合较好,同时相比上述其他模型,该模型具有较好的预测效果。

关键词: 镁合金, 低周疲劳, 疲劳寿命, 熵, 平均应力

Abstract: Through low cycle fatigue experiments of the cast magnesium alloy AZ91D and the wrought magnesium alloy AZ31B at room temperature under stress control, the fatigue life prediction was conducted by the Basquin model, the SWT model and the strain energy-life model. Then, regarding the low cycle fatigue damage of magnesium alloys as an irreversible dissipation process that might be described by the entropy according to the irreversible thermodynamics theory of continuum damage mechanics, and using the mean strain increment per cycle to reflect the effects of the mean stress, a new model for the low cycle fatigue life prediction of magnesium alloys was developed. By this model, the low cycle fatigue life prediction of magnesium alloys was carried out through the experiments mentioned above. Results show that the predicted results are in good agreement with the experimental results. And compared with the other life prediction models, the new model for the low cycle fatigue life prediction of magnesium alloys has a better effectiveness.

Key words: magnesium alloy, low cycle fatigue, fatigue life, entropy, mean stress

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