论文部分内容阅读
飞机发动机引气预冷系统导管固定卡箍服役后发生断裂,通过外观观察、断口宏微观观察、金相组织检查、硬度试验、化学成分分析等方法对卡箍断裂原因进行了综合分析,结果表明:断裂卡箍为高周疲劳断裂;导管设计布局在发动机舱,断裂卡箍处位于导管安装有波纹管端附近,在发动机运转中产生振动,如果卡带与支架装配过程中装配应力过大,会导致外表面边角处应力较大,同时在振动应力作用下,在外表面边角应力集中处形成裂纹并扩展,降低支架的边缘和卡带表面处的应力集中,消除卡带边缘的残余应力,可有效防止卡箍的疲劳断裂。
The rupture of the catheter fixed clamp of the engine air bleed precooling system after service was carried out. The causes of the fracture of the clamp were comprehensively analyzed by the appearance observation, the macro-and micro-observation of the fracture, the metallographic examination, the hardness test and the chemical composition analysis. : Fracture clamp for high-cycle fatigue fracture; catheter design layout in the engine compartment, the fracture clamp is located in the conduit near the bellows installed near the end of the vibration generated in the engine operation, if the cassette and the mounting assembly process too much stress, will Resulting in a large stress at the corners of the outer surface. At the same time, under the action of vibration stress, cracks are formed at the stress concentration points on the outer surface edges and extend to reduce the stress concentration at the edge of the support and the surface of the cassette surface, thereby eliminating the residual stress at the edge of the cassette. Prevent the clamp from fatigue fracture.