【作者】 张成成；

【导师】 姚卫星；

【作者基本信息】 南京航空航天大学 ， 飞行器设计， 2007， 硕士

【摘要】 飞机结构的疲劳品质主要取决于结构的细节设计,结构细节的抗疲劳优化设计在很大程度上决定了整架飞机的使用寿命和检修周期。结构细节抗疲劳优化设计已有不少研究,本文提出了一种新的结构细节抗疲劳优化设计的策略,大大减少了工程结构抗疲劳设计的计算规模,并获得较好的结果。该方法的基本思想是在结构抗疲劳设计方法的指导下选取结构的设计变量,利用拉丁立方体试验设计方法在设计空间里选取设计变量的样本点,对各个样本点利用PCL(Patran Command Language)建立其结构有限元模型并进行结构分析和疲劳寿命估算,得到对应各样本点的响应(结构重量和疲劳寿命),利用这些样本点和响应值建立以疲劳寿命和结构重量为目标的响应面近似模型,近似模型通过回归分析和方差分析后若满足近似要求再以主要目标法解决此多目标优化问题,从而在保证近似模型有效性的情况下获得较好的寻优结果,同时也避免了以往抗疲劳优化设计中大量耗时的有限元建模和分析。起落架扭力臂构件和螺栓连接件的算例表明,本文提出的结构抗疲劳优化方法的策略通用性好,优化结果较为满意。更多还原

【Abstract】 The fatigue quality of the aircraft structures mainly depends on the structural detail design. The fatigue life of the aircraft is decided mostly by structural anti-fatigue design. There are many investigations of anti-fatigue design carried out in the past three decades, but the researches of anti-fatigue optimum design are rare. In this thesis a novel strategy of anti-fatigue optimum design is proposed, it can reduce computing costs and achieve well results.The main idea of the proposed strategy is that structural design variables are firstly chosen with the direction of approaches of anti-fatigue design, then the samples for analysis are created in the variable space with the Latin-Hypercube design of experiment (DOE), after that finite element models corresponding to the samples are built with PCL (Patran Command Language), lastly the response surface model (RSM) of fatigue life and weight using these samples and responses obtained by finite element analysis and fatigue life estimation are set up. Passed the regression analysis and analysis of variance, the response surface approximate model would be solved by the principal objective method which is one of multi-objective optimization solutions. It will obtain well results while the validity of approximate model is remained and avoid time-consuming computation of finite element analysis by former anti-fatigue optimum design.A torque arm of aircraft landing gear and the component of bolt joints are optimized as examples and the results show that this strategy is universal and effective.更多还原