航空发动机叶片TC4钛合金振动疲劳裂纹扩展研究及剩余寿命预测

发布时间：2018-01-02 15:07

本文关键词：航空发动机叶片TC4钛合金振动疲劳裂纹扩展研究及剩余寿命预测　出处：《表面技术》2016年09期 　论文类型：期刊论文

【摘要】：目的研究TC4钛合金的振动疲劳特性及寿命预测。方法通过共振疲劳试验,分析裂纹尖端应力强度因子的变化规律,计算不同应力水平下疲劳裂纹扩展的速率,建立剩余寿命预测计算模型。结果裂纹尖端的应力强度因子是表征裂纹扩展速率快慢的有效参数,与裂纹长度及应力场的大小相关。在裂纹扩展初期应力为274 MPa的条件下,裂纹扩展速率的试验值与计算值吻合较好。通过寿命预测模型计算可知,当初始裂纹为0.5 mm,最终裂纹长度达到5 mm时,在应力为274、366、422 MPa的条件下,振动循环周期分别为36 577、19 090、13 865。结论在应力比为?1的振动条件下,裂纹扩展速率随应力水平的增大而加快,同时初始裂纹长度越长,应力相同时,裂纹扩展速率提高。通过寿命预测模型,可计算出结构件的使用寿命。
[Abstract]:The vibration characteristics and fatigue life prediction of TC4 titanium alloy. Through the method of resonance fatigue test, analysis of crack tip change regularity of stress intensity factor calculation, different rate of fatigue crack propagation under the stress level, the residual life prediction model is established. The stress intensity factor of the crack tip is an effective parameter characterizing the crack growth rate speed, and crack length and stress field size. Extend the initial stress is 274 MPa under the conditions of crack, the crack propagation rate of the test value and the calculated values are in good agreement. The life prediction model calculation shows that when the initial crack is 0.5 mm, the final crack length reached 5 mm, in for 274366422 MPa under the conditions of the vibration cycle were 36 577,19 090,13 865. in conclusion the stress ratio? 1 vibration conditions, the crack growth rate with the increase of the stress level and speed, At the same time, the longer the initial crack length is, the crack growth rate increases at the same time, and the service life of the structure can be calculated by the life prediction model.

【作者单位】：中国民航大学天津市民用航空器适航与维修重点实验室;中国民航大学理学院;
【基金】：民航科技重大专项(MHRD20130204) 中央高校基本科研业务费资助项目(3122015L002)~~
【分类号】：TG146.23
【正文快照】： Received:2016-03-05;Revised:2016-06-03TC4钛合金具有比强度高、密度小、耐蚀性好、优良的韧性和焊接性等优点,在航空航天、石油化工、造船、汽车等领域都得到成功的应用。结合其性能优势,民用航空发动机的叶片和涡轮盘等重要部件大多采用TC4材料制作而成,但其在高温高压、

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