某抽水蓄能电站顶盖螺栓断裂原因分析

某抽水蓄能电站的顶盖螺栓发生断裂,通过螺栓断口分析可以发现,大部分螺栓存在疲劳裂纹, 疲劳裂纹均起源于螺纹根部,裂纹源形成的尖端应力集中使螺栓发生断裂。为了分析螺栓断裂的原因,对螺栓的直径进行复核计算,通过计算可以发现,在满足预紧要求的前提下,螺栓的直径偏小,其疲劳强度计算安全系数偏小是螺栓发生疲劳破坏的根本原因。通过增大螺栓直径可以既满足螺栓设计预紧要求,也满足螺栓的疲劳设计要求。

Causes of Header Bolt Fracture of a Pumped Storage Power StationZ

Fractures were found in the header bolts of a pumped storage power station. According to bolt fracture analysis, fatigue cracks originated in the thread root were found in most of the bolts. Tip stress concentration induced by the source of cracks led to bolt fracture. To analyze the cause of bolt fracture, the diameter of the bolt was calculated and checked. It was found that the bolt diameter was small when the preloaded condition of the bolts was satisfied, and the fatigue strength calculation safety factor was small as well, which would lead to fatigue damage. Increasing the bolt diameter could not only meet the bolt preloading requirement, and also meet the requirement of bolt fatigue design.