【作者】 陈水根；

【导师】 黄其青； 张志林；

【作者基本信息】 西北工业大学 ， 固体力学， 2002， 硕士

【摘要】 本文主要就起落架支柱外筒关键危险部位，系统地从安全寿命分析、耐久性经济寿命分析及损伤容限分析等方面对其进行评估。 主起落架疲劳载荷谱在没有飞行实测数据的情况下，本文以《军用飞机起落架标准载荷谱》GJB3099-97为框架，结合《军用飞机强度和刚度规范》GJB67.6-85的有关规定编制**机主起各典型任务段疲劳载荷谱。这比单纯的设计谱更符合实际使用情况。 疲劳安全寿命评定采用*型机和**型机主起支柱外筒关键危险部位成组模拟件寿命试验对比和寿命计算对比进行。利用原型机（*型机）主起全尺寸疲劳试验结果，通过综合修正，将光滑试件的S∽N曲线修正为构件危险部位的S∽N曲线，使寿命计算结论更为可靠。 耐久性经济寿命分析采用改进的裂纹萌生方法，此方法已多次应用于国内飞机结构的经济寿命评定中，所得结果可靠。 在损伤容限分析中，本文认为关键危险部位可能萌生的裂纹形态为表面裂纹与棱边角裂纹；损伤容限分析模型选用广义Willenborg模型；为保证剩余强度要求，本文通过在裂纹扩展计算中以应力强度因子达到K_1c／1.2作为终止条件来实现。 本文最后给出了**型机主起支柱外筒的首翻期为4000起落、检查间隔为1500起落、总寿命为6000起落的初步结论。更多还原

【Abstract】 From the view of safety life, durability and damage tolerance, the article mainly discuss the assess of key position of strut cylinder.Because there is no measured load spectrum, the article gives the typical task fatigue load spectrum of main landing gear of some aircraft based on <<Warplane Landing Gear Standard Load Spectrum>> GJB3099-97 and under the relational stipulation of the <<Warplane Strength and Stiffness Specification>> GJB67. 6-85. It is closer to the practicality than the method of purely designing spectrum.Fatigue safety life assesses use compare methods, which are, comparing of life test and life calculation of type A aircraft and type B aircraft main landing gear strut cylinder key danger position in group simulators. Using results of prototype aircraft (type A aircraft) main landing gear full-scale fatigue test, we can amend the S~N curve of slick test part to the S~N curve of component danger position by amending synthetically, and so that the conclusions of life calculation are more reliable.Improved crack sprout method is adopted in durability economy life analysis, which method is applied time after time to the economy life assess of domestic aircraft structure, and the result is reliable.During damage tolerance analysis, the probably crack types of key danger position are surface crack and edge angle crack in this article. Damage tolerance analysis model select generalized Willenborg model. To meet the residual strength requirement, it takes the stress intensity factor K1C/1. 2 as the termination condition in crack propagation calculation in the article.In the end, the article gives the conclusion as following: the main landing gear strut cylinder of type B aircraft first repairing period is 4000 landing and take-offs, examine interval is 1500 landing and take-offs and the total life is 6000 landing and take-offs.更多还原