东风-50拖拉机在使用中曾发生过前桥断裂的事例多起,从断裂的前桥中观察到,破坏的部位大多集中在十字接头两端的焊缝区和两个空心圆柱相关的过渡圆角处。从对十字接头进行的载荷谱室内模拟疲劳试验的研究中也证实了上述两个部位是薄弱的地方。引起断裂的原因是多方面的:设计不合理,产生过高的应力集中;焊接质量不高; There are many cases of DFB-50 tractor used in the front axle, and it is observed from the broken front axle that the damaged parts are mainly concentrated in the weld zone at the two ends of the cross joint and the transitional fillets related to two hollow cylinders Department. The study of the fatigue test in the load spectrum of a cross-over joint also confirmed the weakness of these two locations. The causes of fracture are many: design is not reasonable, resulting in high stress concentration; welding quality is not high;