The results showed that the fatigue fracture of the connecting head happened first, which was related both to the working stress and to the processing of this part.

• 结果表明，连杆盖首先发生疲劳断裂，随后导致连杆螺栓的断裂，而这种断裂既与应力有关，又与零件的加工工艺有关。