多点分布载荷作用下TBM刀盘裂纹萌生寿命预测
Prediction of Cutterhead Crack Initiation Lifetime for Tunnel Boring Machine under Multi-point Distribution Loads

隧道掘进机（TBM）是用于隧道掘进的大型复杂工程机械，刀盘是TBM的关键部件承载数十把滚刀与岩石作用。掘进时的反力和扭矩作用在刀盘上容易产生裂纹降低寿命，刀盘的寿命制约着TBM的寿命。为了研究刀盘的寿命，提出了综合运用多体动力学和有限元计算刀盘动应力的一种方法并使用此方法计算了刀盘的动应力，计算结果与实测数据的均值误差仅为13%。对动应力进行统计计数并按照幅值的分布规律将其分为八级，结合材料的应力-寿命曲线对刀盘裂纹萌生寿命进行了预测，预测结果表明刀盘的裂纹萌生寿命为84天。裂纹萌生寿命预测结果可以为TBM刀盘的抗疲劳设计提供参考，也可以为安排施工检修周期提供依据。
Tunnel boring machine (TBM) is a kind of the complex engineering machinery in tunnel boring. Cutterhead is a key part of TBM, which holds tens of cutters to bore. The force and torque on cutterhead are easy to generate cracks and reduce its lifetime. TBM lifetime depends on cutterhead lifetime. To investigate cutterhead lifetime, a method to calculate stress with dynamics and finite element method has been proposed. The calculation cutterhead stresses have been compared with that via in-situ experiement, which the error is only of 13%. According to the stress distribution, the dynamic stresses have been divided into eight levels. With the stress-lifetime curve of material, the prediction initiation lifetime of cutterhead is of 84 days. This result could offer anti-fatigue reference for cutterhead design and maintenance period accordance for construction