Dynamic Modeling and Nonlinear Vibration Analysis of Dual-Drive Feed System Considering the Moving Contact Interfaces

Dual-drive feed systems are widely adopted in high-end CNC machines because of their high precision, rigidity, and operational stability. Vibration suppression during machining is critical to maintaining feed accuracy and surface quality; however, the presence of multiple moving contact interfaces introduces pronounced nonlinearities arising from relative motion, frictional effects, and elastic restoring forces. In this study, Hertz contact theory is employed to model the principal moving interfaces in a dual-drive feed system and to derive the load- and preload-dependent coupling stiffness characteristics. A system-level dynamic model is then established using the Craig-Bampton component mode synthesis method, in which the nonlinear restoring forces of the moving interfaces are incorporated. The steady-state nonlinear vibration response is solved in the frequency domain by the harmonic balance method (HBM), enabling a systematic investigation of the nonlinear vibration behavior under different preloads, external loads, and worktable displacements. Frequency-sweep experiments are conducted to validate the proposed modeling and solution framework. The proposed approach provides a theoretical basis for understanding nonlinear vibration mechanisms and for improving high-precision synchronous control of dual-drive feed systems.