The results indicated that the fracture mode is the fatigue failure. 结果表明，其断裂形式为弯曲疲劳断裂。
The fatigue fracture reason of the weld seam at the back supporting rod of the main reductor of an aircraft has been analyzed by fractography and metallographic test. 对某飞机主减速器后撑杆焊缝疲劳断裂原因作了分析。
