FEA-Based Vibration Mode Identification and Effective Mass Participation Analysis of a Concentric Double-Flange Butterfly Valve at Multiple Opening Angles

This study presents a modal analysis of a concentric double-flange butterfly valve (DN-500, PN-10) to assess its dynamic characteristics at multiple opening angles. The investigation employed Finite Element Analysis (FEA) to evaluate the valve structure’s natural frequencies, mode shapes, and effective mass participation factors (EMPFs) at 30°, 60°, and 90° respectively. The valve geometry was discretized using curvature-based mesh, and linear elastic isotropic material properties of 1023 carbon steel. Modal analysis was conducted to solve the governing eigenvalue problem and determine the dominant modes of vibration. The analysis revealed that lower-order modes exhibit global deformation primarily along the disk, whereas higher-order modes show significant localized deformation around the shaft-bearing interface, indicating coupled torsional-translational dynamics. EMPF values demonstrated that the X-direction dominates the dynamic response at higher modes, particularly at frequencies near 1153 Hz, with Mode 3 and Mode 4 showing critical mass contributions. Comparative EMPF distributions across the three valve openings highlight directional sensitivity and suggest potential resonance zones that may induce structural instability. The outcomes provide identification of potential resonance zones that could guide a development of design improvements and fatigue resistance of butterfly valves in industrial flow regulation systems.