Vibration characteristic analysis of a rack-climbing lift platform based on a rigid-flexible coupled model

To address the limitations of traditional multi-rigid-body models in accurately analyzing the vibration characteristics of rack-climbing lift platforms, this study proposes a rigid-flexible coupled dynamic equation and develops a flexible-body substructure reduction method to enhance simulation accuracy while reducing computational complexity. A rigid-flexible coupled simulation model is constructed by integrating ANSYS APDL with ADAMS, enabling an organic coupling between flexible components and rigid bodies. Axial vibration characteristics of the platform are simulated using four models-rigid, multi-flexible coupled, flexible-driven coupled, and rigid-flexible coupled. Results indicate that the Z-direction vibration is similar to the X-direction, with maximum amplitudes of 1.03mm and 1.34mm occurring during the startup phase, whereas the Y-direction amplitude reaches 7mm, representing increases of 579% and 422% relative to the Z- and X-directions, respectively. These findings demonstrate the inadequacy of rigid-body models for effective vibration analysis. Compared with the multi-flexible and flexible-driven coupled models, the rigid-flexible coupled model exhibits smoother transition in vibration response and more pronounced amplitudes, confirming its validity. Further parametric analysis under varying operating speed, load magnitude, eccentric loading, and braking time reveals that eccentric loading effects are condition-dependent, while load magnitude and operating speed significantly influence platform vibration. Finally, experimental validation of axial vibration and vibration acceleration confirms the accuracy of the proposed model. This study provides a theoretical foundation and reliable modeling framework for structural optimization, comfort design, and vibration behavior analysis of lift platforms.