民机全尺寸结构疲劳试验支持夹具设计研究

Research on Support Fixture of Full-Scale Aircraft Structure Fatigue Test

民机的结构设计必须按照耐久性/损伤容限要求进行,因其分析方法不像静强度那样成熟,适航当局在进行符合性审查时,特别注重全尺寸结构的疲劳和损伤容限试验。在部件试验中,因各部件试验可同时独立进行、载荷谱全面、加载点少及进度快,因此广泛用于民机研制过程中。部件疲劳试验的支持夹具提供与原结构相当的支持刚度。文章通过对某飞机襟翼子翼疲劳试验支持夹具的设计与分析,验证试验支持段可提供真实支持。研究表明,随着试验件与真实支持连接的静不定阶数增大,过渡段的设计趋于复杂。当支持夹具的设计过于复杂时,为保证结果准确有效,建议采用与试验件相连接的真实结构作为支持段。

Airworthiness authorities pay more attention on full-scale structure fatigue and damage tolerance test when certifying compliance of civil aircraft for its analytical methods are not so accurate as that of static strength. According to the merits that component tests could be operated separately and covering more complete load spectrum while with less loading point and short period, full-scale component structure tests are more and more adopted in civil aircraft development. In component test, the support fixture should provide the similar boundary conditions as true structure. In the paper, the designing of support fixture of full-scale aircraft structure fatigue test is investigated through analyzing the fatigue test of a sub-flap structure. The support fixture would become complicated when the order of statically indeterminate of the join in true structure increases. The conclusion that true structure with connection with specimen could be adopted as support fixture to ensure the results is carried out in the end.