【作者】 刘强；

【导师】 朱顺鹏；

【作者基本信息】 电子科技大学 ， 工程硕士（专业学位）， 2018， 硕士

【摘要】 作为飞机的动力装置,航空发动机对飞机的性能和安全性起着至关重要的影响。愈趋严酷的工作条件致使发动机转子部件承受着复杂的工作载荷,这意味着在提高飞机发动机的推重比、燃油使用效率以及发动机总体性能的同时,必须对其主要零部件所具备的可靠性给予足够的重视。作为航空发动机限寿件之一,高压涡轮盘常在高温、高压环境下高转速运转,一旦出现微小裂纹,就可能给飞机造成无法估量的灾难性后果。为了保证航空发动机的安全可靠运行,要求高压涡轮盘必须具有相应的高可靠性。针对上述问题,本论文对某型号航空发动机高压涡轮盘开展了如下研究工作:1)涡轮盘结构疲劳寿命预测中的不确定性量化。高压涡轮盘等热端部件通常在多重不确定因素影响下承受着复杂的工作载荷。这些不确定因素对其疲劳寿命预测与可靠性评估过程起着不可忽视的影响。本论文建立了基于拉丁超立方抽样方法来确定材料属性参数和载荷随机性影响的有限元仿真框架,材料不确定性是通过Chaboche模型与Mason-Coffin方程传递并反馈到结构应力/应变响应。2)涡轮盘的概率疲劳寿命预测与结构可靠性分析。在实际工程当中,高压涡轮盘经常承受着复杂多轴载荷,针对此,基于Fatemi-Socie(FS)模型预测了该高压涡轮盘的疲劳寿命。通过开展耦合多重不确定因素影响的高压涡轮盘结构有限元分析,根据有限元仿真分析结果获得了其概率疲劳寿命,在此基础上,对处于多重不确定因素影响下的高压涡轮盘进行了疲劳可靠性及灵敏度分析。3)考虑载荷相互作用及次序效应的非线性累积损伤模型。高压涡轮盘的工作载荷通常为变幅载荷,考虑到变幅载荷作用下Miner线性损伤累积理论的准确性和适用性并不理想,本论文提出了基于等损伤曲线的新非线性疲劳损伤累积模型。通过引入大量的试验数据及模型对比,验证了所提出模型的准确性与可行性。4)基于累积损伤的涡轮盘疲劳寿命预测与可靠性分析。为了考虑载荷间相互作用效应及其加载次序效应对涡轮盘结构寿命的影响,本论文运用新提出的非线性损伤累积模型预测了高压涡轮盘的疲劳寿命及其疲劳可靠性。更多还原

【Abstract】 As the power device of airplane,aero engine has shown a decisive impact on the performance of aircraft flight capability and safety.Harsh working condition makes most of engine components bear complicated working loads,which means that while increasing the thrust-to-weight ratio of aircraft engine,specific fuel consumption and the overall performance of the aircraft engine,the reliability of the major parts have to be paid enough attentions.As one of fatigue critical components of aircraft engines,high pressure turbine(HPT)disc works under high rotational speeds and high temperatures.Once it appears micro cracks,it may lead to immeasurable disastrous consequences for the aircraft.In order to ensure that the engine can operate safely,high reliability and considerable performance of the HPT disc are desired.Considering the issues mentioned-above,in this thesis,researches on an HPT disc have been carried out:1)Uncertainty quantification in fatigue life prediction of turbine disk.Engine hot section components like the HPT discs withstand complex loadings under multi-source uncertainties.The influence of these uncertainties on structural response of HPT discs cannot be ignored during its fatigue life and reliability assessment.In this study,seversal FE simulations are established to quantify the influence of material variability and load variations by using the Latin hypercube sampling.In particular,material response variability is modeled by combining the Chaboche model with Manson-Coffin equation.2)Probabilistic fatigue life prediction and structural reliability analysis of the HPT disc.In practice,engine component like HPT discs is frequently subjected to complex multiaxial loadings.Therefore,the Fatemi-Socie(FS)damage criterion is used to predict the fatigue life of the HPT disc.From the results of FE analysis of the HPT disc,probabilistic fatigue life of the HPT disc is calculated,based on which,the structural fatigue reliability and sensitivity analysis of the HPT disc under multiple sources of uncertainty has been carried on.3)Nonlinear cumulative damage model considering the influence of loading sequences.Usually the HPT disc is subjected to variable amplitude loading during service time.Considering that the accuracy and applicability of the Miner’s rule under variable amplitude loadings is not ideal,a new nonlinear fatigue damage accumulation model is proposed based on the isodamage curves.Through introducing a lot of test data and some commonly used prediction models,the accuracy of the proposed model is verified.4)Fatigue life prediction and reliability analysis of turbine disk based on cumulative damage.In order to consider the influence of the amplitude variation of loading and the loading sequences,the proposed damage accumulating model is used to predict the fatigue life of an HPT disc,and its structural fatigue reliability is also studied.更多还原