复杂地质条件下TBM撑靴液压缸导向铜套微动损伤分析

Fretting Damage of Copper Sleeve Gasket in Gripper Cylinder of TBM Excavating in Complex Geological Structures

为分析硬岩掘进机的撑靴液压缸在强振动工作环境下内衬铜套断裂的损伤机理,建立考虑撑靴与围岩接触刚度、缸筒和活塞杆接触面处等效刚度和液压油等效刚度的撑靴液压缸系统的集中参数动力学模型。研究不同支撑刚度条件下,撑靴液压缸导向套和内衬铜套接触面的法向力、切向力、法向压缩量和切向滑移量的变化规律。基于Hertz理论,分析掘进机在不确定地质条件下掘进时导向套与内衬铜套界面之间的接触载荷分布规律。根据连续介质损伤力学建立了内衬铜套结构含损伤材料本构模型,以液压缸动力学模型得到不同接触刚度下的内衬铜套接触面处的微动载荷为初始条件,分析了撑靴液压缸的内衬铜套的损伤演化规律。结果表明随着支撑刚度的增大,切向力和切向滑移减小,损伤的萌生和演化速率降低。适当提高围岩和撑靴之间的接触刚度,降低撑靴液压缸导向铜套的损伤概率。

The damage mechanism of copper sleeve gasket in the gripper cylinder of TBM subjected to strong vibration is the main concern. A lumped mass parameter dynamic model of the gripper cylinder in TBM is firstly established considering the contact stiffness between the rock and the gripper shoes, the equivalent stiffness at the contact interface of the barrel and the piston rod, and the equivalent stiffness of the hydraulic oil. The changing rules of the normal force, the tangential force, the normal compression displacement and the tangential slip at the contact interface between the guide sleeve and the copper sleeve gasket are studied under different contact stiffness at the rock interface. The contact load distribution at the interface between the guide sleeve and the copper sleeve gasket is calculated based on the Hertz theory when TBM excavated in the uncertain geological strata. Then the damage constitutive model of copper sleeve gasket is developed. The damage evolution rules of the copper sleeve gasket in the gripper cylinder are investigated based on the fretting loads at the contact interface that are obtained from the dynamic model under different contact stiffness between the rock and the gripper shoes. Furthermore, the influences of the tangential force and the tangential slip on the damage evolution rules of the copper sleeve gasket are analyzed. The results show that both the tangential force and the tangential slip decrease with the increasing contact stiffness at the rock interface. Moreover, the damage initiation and evolution rate of the copper sleeve gasket also decrease with the contact stiffness. It could be concluded that the damage of the copper sleeve gasket of the gripper cylinder can be reduced when the contact stiffness of the surrounding rock and the gripper shoes can be increased.