| 引用本文: | 刘德俊,田干,李玉龙,等.含缺陷2195-T8铝锂合金疲劳断裂与仿真分析.[J].国防科技大学学报,2024,46(5):168-178.[点击复制] |
| LIU Dejun,TIAN Gan,LI Yulong,et al.Fatigue fracture behavior and simulation analysis on 2195-T8 Al-Li alloys with defects[J].Journal of National University of Defense Technology,2024,46(5):168-178[点击复制] |
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| 含缺陷2195-T8铝锂合金疲劳断裂与仿真分析 |
| 刘德俊1,田干1,李玉龙2,金国锋1,张炜1 |
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(1. 火箭军工程大学 导弹工程学院, 陕西 西安 710025;2. 中国运载火箭技术研究院, 北京 100076)
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| 摘要: |
| 针对轻质铝锂合金服役环境下的疲劳断裂问题,将第三代铝锂合金2195-T8作为研究对象,通过恒幅拉-拉疲劳试验和等效裂纹模型方法对含缺陷2195-T8 铝锂合金疲劳裂纹扩展行为进行试验与数值仿真分析。研究结果表明:疲劳裂纹萌生于缺陷底部,裂纹扩展速率在表面长度方向最快,而在深度方向扩展最慢；2195-T8 铝锂合金疲劳断口具有典型的分层现象,且合金的分层极大地阻碍裂纹尖端深度方向扩展,导致裂纹分叉；裂纹分叉后扩展速率急剧升高,尖端塑性区域体积迅速增加,使合金进入快速断裂区。以上结果综合说明,含缺陷2195-T8铝锂合金疲劳寿命受裂纹扩展倾向性、分层影响而减少。 |
| 关键词: 疲劳断裂 铝锂合金 裂纹扩展 有限元 |
| DOI：10.11887/j.cn.202405018 |
| 投稿日期：2022-05-17 |
| 基金项目:国家自然科学基金资助项目(52075541)；陕西省自然科学基金资助项目(2022JM-243) |
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| Fatigue fracture behavior and simulation analysis on 2195-T8 Al-Li alloys with defects |
| LIU Dejun1, TIAN Gan1, LI Yulong2, JIN Guofeng1, ZHANG Wei1 |
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(1. College of Missile Engineering, Rocket Force University of Engineering, Xi′an 710025, China;2. China Academy of Launch Vehicle Technology, Beijing 100076, China)
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| Abstract: |
| Aiming at the fatigue fracture problem of light Al-Li alloy in service environment, the third generation aluminum-lithium alloy 2195-T8 was taken as the research object. Experimental and simulation of the fatigue crack propagation behavior of the third-generation 2195-T8 Al-Li alloy with defects was investigated by constant amplitude tensile fatigue test and equivalent crack model. The results show that the fatigue crack starts at the bottom of the defect, and the crack growth rate is the fastest in the surface length direction, but the slowest in the depth direction. The fatigue fracture of 2195-T8 aluminum-lithium alloy has a typical delamination phenomenon, and the delamination of alloy greatly hinds the crack tip depth direction expansion, resulting in crack bifurcation. After the crack bifurcation, the propagation rate increases sharply, and the plastic region volume at the tip increases rapidly, which makes the alloy enter the rapid fracture zone. The above results show that the fatigue life of 2195-T8 Al-Li alloy with defects is reduced by crack propagation inclination and delamination. |
| Keywords: fatigue fracture Al-Li alloys crack propagation finite element |
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