飞机起落架轮毂断裂机理研究

 用光学金相、X光透视、断口金相及红外光谱分析技术分析了飞机主起落架轮毂断裂件的冶金铸造质量、断裂机理以及相关失效件轴承、轮轴的损伤特征 ,经实验室模拟试验再现了断裂件断口的宏观、微观形貌。确定了 ZM5 T4铸镁合金轮毂断裂性质和原因 ,为防止同类事故发生提供了可靠依据

INVESTIGATION ON FRACTURE MECHANISM OF AN AIRCRAFT LANDING GEAR HUB

The fracture surface of an aircraft landing gear hub and the metallurgical quality of ZM5T4 cast magnesium alloy as well as the damage feature of its related components (bearing,shaft) were examined by metallography, X\|ray defectoscopy, fractography and infrared spectrometry in laboratory. The appearances of fractosurfaces simulated at various testing temperatures were obtained. Fracture of the hub was brittle intergranular fracture at high temperature. Local fracture temperature approached the materials binary eutectic temperature. Laboratory examination and airfield investigation results indicated that the failure of the hub was not related to metallurgical quality, but to the small assembling gap of the landing bearing system. It induced poor lubrication, scratch and high temperature crack of the bearing component and the hub. The small assembling gap of the bearing system was considered to be the basic cause of the aircraft landing gear hub failure at high temperature.