某型涡扇航空发动机涡轮轴有限元及寿命分析

发布时间：2018-01-19 21:03

本文关键词： 涡轮轴有限元分析疲劳寿命寿命试验　出处：《电子科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：航空发动机作为飞机重要的动力装置,其工作状态的稳定性及可靠性直接影响到飞机的正常使用。其中,航空发动机主轴主要包括风扇轴、低压涡轮轴和高压涡轮轴等,承担着连接发动机周围零部件和传递循环工作载荷的作用。在工作状态下,涡轮轴长期处在高温环境中,并随飞行状态的变化不断承受高、低周疲劳载荷复合作用。涡轮轴传递载荷最大,工作环境较为恶劣,极易发生疲劳失效。因此,涡轮轴的疲劳寿命将直接影响航空发动机的正常使用,一旦发生疲劳失效将引起重大事故。为了提高发动机工作的安全性及使用寿命,给予发动机涡轮轴有关维修及更换提供指导意见,航空发动机涡轮轴的疲劳可靠性问题受到广泛关注和研究。本文结合国内外航空发动机主轴疲劳寿命研究现状,对某型涡扇航空发动机涡轮轴的疲劳寿命问题进行研究。本文研究内容主要包含以下几个部分:首先,根据航空发动机涡轮轴的工作原理、结构及装配情况,确定涡轮轴的约束情况和外部高、低周疲劳载荷的类型及计算方法,如轴向力、扭矩和弯矩等。根据飞机飞行状态确定需要分析的工作任务剖面,并得到对应工作条件下的外部载荷值及载荷施加位置。结合ANSYS Workbench有限元软件,建立并简化涡轮轴的有限元模型,然后确定恰当的材料输入模型及边界条件,模拟涡轮轴的实际工作状态,分别完成涡轮轴在低周疲劳载荷和高低周疲劳载荷复合下的有限元分析,计算分析得到涡轮轴危险部位及其应力应变分布情况。其次,考虑到外部载荷对涡轮轴疲劳寿命的影响,结合国内外航空发动机主轴疲劳寿命预测方法研究现状,分别研究了基于局部应力应变法的高、低周疲劳寿命预测模型,基于临界面法的高、低周疲劳寿命预测模型,以及线性疲劳累积损伤原理。然后结合有限元分析结果,利用上述方法分别完成涡轮轴危险部位的高、低周疲劳寿命预测,并对预测计算结果进行了对比分析。最后,为验证涡轮轴疲劳寿命预测结果的准确性,研究了涡轮轴疲劳寿命试验载荷的确定方法以及具体试验实施方案。根据疲劳试验条件和要求,对涡轮轴进行有限元分析,并计算涡轮轴危险部位的疲劳寿命,以此验证疲劳试验设计的准确性。
[Abstract]:The stability and reliability of aeroengine, as an important power device of aircraft, have a direct impact on the normal use of aircraft. Among them, the main axis of aeroengine mainly includes fan shaft. The low-pressure turbine shaft and the high-pressure turbine shaft bear the function of connecting the parts around the engine and transferring the cyclic working load. In the working state, the turbine shaft is in the high temperature environment for a long time. With the change of flight state, the turbine shaft is subjected to high and low cycle fatigue loading. The turbine shaft has the largest transfer load, and the working environment is relatively bad, so fatigue failure is easy to occur. The fatigue life of turbine shaft will directly affect the normal use of aero-engine, once the fatigue failure will cause serious accidents, in order to improve the safety and service life of the engine. Provide guidance on maintenance and replacement of engine turbine shafts. The fatigue reliability of aeroengine turbine shafts has received extensive attention and research. In this paper, the research status of fatigue life of aeroengine spindle at home and abroad is considered. The fatigue life of turbine shaft of a turbofan aero-engine is studied. The main contents of this paper are as follows: firstly, according to the working principle, structure and assembly of turbine shaft of aero-engine. Determine the constraints of the turbine shaft and the external high and low cycle fatigue load types and calculation methods, such as axial force, torque and bending moment, etc. According to the flight status of the aircraft to determine the work mission profile to be analyzed. The external load value and load applied position under the corresponding working conditions are obtained, and the finite element model of turbine shaft is established and simplified with ANSYS Workbench finite element software. Then the proper material input model and boundary conditions are determined to simulate the actual working state of turbine shaft and the finite element analysis of turbine shaft under low cycle fatigue load and high and low cycle fatigue load is completed respectively. The dangerous part of turbine shaft and its stress-strain distribution are obtained by calculation and analysis. Secondly, the influence of external load on fatigue life of turbine shaft is considered. Combined with the current research situation of fatigue life prediction method for aeroengine spindle at home and abroad, high and low cycle fatigue life prediction models based on local stress-strain method and high fatigue life prediction model based on critical plane method are studied respectively. The prediction model of low cycle fatigue life and the principle of linear fatigue cumulative damage are used to predict the high and low cycle fatigue life of turbine shaft respectively. The prediction results are compared and analyzed. Finally, to verify the accuracy of the prediction results of turbine shaft fatigue life. According to the fatigue test conditions and requirements, the finite element analysis of turbine shaft is carried out, and the fatigue life of turbine shaft is calculated. The accuracy of fatigue test design is verified.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：V235.13

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