The shield main drive seal is composed of a labyrinth seal and four lip seals. The use process of the first seal of the shield machine main drive includes multiple stages. The lip seal will be greatly deformed during assembly and pressurization. Therefore, the sealing leakage process is actually a two-way fluid-structure interaction (FSI) process. However, the traditional two-way FSI finite element method must have a continuous flow field because the current dynamic mesh technology cannot solve the problem of the topological filling of the discontinuous flow field. In the initial interference assembly condition of the shield main drive seal, the seal flow fields are independent of each other, which makes the leakage simulation calculation process extremely complicated. Furthermore, the deformation process of the main drive seal under the fluid pressure difference not only involves a flow field calculation under large deformation but also includes complex calculation conditions such as the hyperelasticity of the main drive seal, two-phase flow, and non-Newtonian fluids. To analyze the leakage characteristics of the shield main drive sealing system, an FSI calculation method is established. The method is based on Abaqus and Fluent, and it can solve complex calculation conditions such as the hyperelasticity of the main drive seal, two-phase flow, and non-Newtonian fluids. First, the method calculated the assembly process of the sealing ring by Abaqus and given the initial boundary pressure on both sides of the sealing ring to make the clearance slightly open, which is the precondition for calculating the flow field. Second, we extracted the deformed solid model and rebuild the model. Then, the deformed model was used to calculate the flow field in Fluent, and when the flow field reaches a steady state, the fluid pressure on both sides of the sealing ring was collected. Because the grease flows slowly, the dynamic pressure and static pressure differ by an order of magnitude, so the calculation used static pressure in this paper. Then, the flow field pressure was transferred to the solid model, and the deformation of the seal ring was recalculated by Abaqus. Finally, the above calculation process was repeated until the calculation results of the two models converge. The shield main drive sealing experimental system is built, and the effectiveness of the method is experimentally verified. Through the calculation and analysis, it is concluded that when the initial sealing gap is large, the backflow will not produce because of the large pressure drop of the grease in the second chamber. Under the design parameters, the flow gradually reaches a steady state, and the seal is no longer deformed. The grease in the first chamber tends to flow back to the second chamber, but finally, the backflow phenomenon is not produced. A complete simulation calculation method is proposes for the study field of shield main drive sealing. The FSI model and results provide a theoretical basis and reference for research on the sealing structure performance of the main drive seal.

The sealing performance of safety valves relies on a tight fit between the spool and the seat. To avoid jamming, a larger fitting clearance is designed for spool guidance, which makes the spool deflection excessive, leading to a gap in the sealing interface and affecting the sealing performance. Based on ABAQUS, this paper conducts a mechanical analysis of the sealing interface under the conditions of spool deflection and studies the relationships between the spool deflection angles and sealing failure. By analyzing the simulation results, the maximum deflection angles of the spool are determined under the premise of ensuring the sealing performance at different operating temperatures. A complete simulation calculation method is proposed for the study field of valve sealing. The results provide a theoretical basis and reference for the design of fitting clearance and sealing part size of the valve.