A Synergistic Theoretical and Experimental Study on the Dynamic Behavior of Multi-Layer Gas Foil Thrust Bearings: Role of Gas Film and Multi-Layer Interactions

Multi-layer gas foil thrust bearings (GFTBs) are increasingly utilized in high-speed equipment due to their superior environmental adaptability and capacity for large structural deformations. This study investigates the dynamic performance of multi-layer GFTBs through a refined analytical framework validated by experimental results. In the modeling phase, an equivalent structural model was first developed via finite element analysis (FEA) to quantify the stiffness and damping of the foil structure. By integrating these parameters into the governing equations that define the interaction between foil compliance and gas film thickness, a comprehensive dynamic performance model was established through the integration of compressible gas lubrication theory and the small-perturbation method. To verify the theoretical predictions, a high-speed GFTB test rig was developed for dynamic excitation testing. The comparative results reveal the evolution of dynamic coefficients across varied operating conditions, offering a technical basis for the design optimization and stability assessment of multi-layer GFTBs.