Dynamic modeling and analysis of rotating beams with partially covered enhanced active constrained layer damping treatment

A new dynamic model for vibration analyses of rotating flexible beams with partially covered enhanced active constrained layer damping (EACLD) treatment is developed. To improve the previous EACLD beam modeling method that only considers the edge element stiffness, the edge element of the EACLD patch is modeled as an equivalent spring with attached point mass so that the mass effect of the two added edge elements are included. The discrete rigid-flexible coupled dynamic equations of the hub-beam systems with EACLD treatment in the open-loop and closed-loop cases are derived by using the assumed mode method and Lagrange's equations. The effect of the angular velocity, edge element stiffness, edge element mass, and coverage ratio of the EACLD on the vibration characteristics of the system are investigated. Simulation results show that the edge element stiffness will increase the natural frequencies of the system and make the system become stiffer, while the edge element mass will decrease the natural frequencies of the system. Results from the traditional ACLD beam model, the EACLD beam model without edge element mass and the present EACLD beam model with edge element mass are also compared with each other. It is indicated that the mass effect of the added edge elements should be considered in practical applications and it could even play a positive role in stiffness or damping regulation of systems in conjunction with the vibration controller design. (C) 2019 Elsevier Ltd. All rights reserved.