基于裂纹失效区域的分体式刀盘可靠性计算

全断面岩石掘进机(tunnel boring machine,TBM)工作时刀盘表面会产生大量裂纹,针对这种情况提出一套裂纹区域划分法,在此基础上建立可靠度计算模型.首先,根据受力及结构形式的不同划分刀盘易发生裂纹的危险区域,然后运用雨流计数法获取应力幅值.以裂纹疲劳损伤累积为基本变量,创建TBM刀盘裂纹扩展形式的可靠度计算模型.以中天山隧道工程TBM刀盘为例,刀盘易发生裂纹的部位可划分为10个区域.TBM掘进4 km时可靠度的计算结果与实际工程相符.刀座焊接处最易发生疲劳破坏,维修时应采取措施防止其裂纹扩展.

Split Cutter Head Reliability Calculation Based on Crack Failure Regions

A calculation model of reliability was developed based on the method of dividing crack regions on the surface of TBM (tunnel boring machine )cutter head. The dangerous area was divided on the basis of different stress and structure， and the stress amplitude spectrum was obtained by rain-flow counting. To calculate the reliability， a model of cracks extension was built with crack fatigue damage accumulation as basic variable. For example， dangerous areas of the TBM cutter head used on Zhongtianshan tunnel engineering were divided into 10 according to crack-resistance， and the calculated reliability in TBM tunneling for 4km was consistent with the reality. At this stage， fatigue damage most likely occurred on cutter saddle welding， therefore， measures should be taken to prevent the crack growth during repairs.