An advanced flexible dynamic model and experimental verification for armature assembly in servo valve

The armature assembly is the core component of servo valves, making its dynamic characteristics critical to both operational performance and stability studies - particularly requiring broadband multi-modal dynamic analysis for stability investigations. To efficiently and accurately determine the characteristics of the servo valve, a multi-beam coupled model (MBCM) of the armature assembly has been developed. The finite element method (FEM) and experiments were employed to validate the accuracy of the multi-beam coupled model. Experimental results show that the proposed model is not only valid for simplified armature assemblies, but also remains applicable to real ones. While maintaining excellent first-modal accuracy, minor reductions in precision were observed in high-frequency predictions, attributable to discrepancies between the higher-order modal shape deformations of the armature and the fundamental assumptions of the MBCM. In the analysis of self-excited vibrations in servo valves, the servo valve model based on MBCM accurately predicts vibration patterns consistent with experimental observations- a capability not achievable by existing models, demonstrating the distinct advantages of the MBCM over current methodologies.