Practical flutter speed formulas for structures with mass unbalance

IF 7.1 1区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Mechanical Sciences Pub Date : 2025-03-24 DOI:10.1016/j.ijmecsci.2025.110182

Zuopeng Wen , Genshen Fang , Yaojun Ge

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Abstract

Clarifying the evolution mechanism of flutter speed through simple formulas has long been challenging due to complex coupling mechanisms and numerous system parameters, particularly for structures with mass unbalance, e.g., airfoils, flutter-based energy harvesting (FEH) systems, and transmission line conductors. This study addresses the challenge by deriving explicit formulas for flutter speed in a vertical-torsional coupled system, offering a systematic framework to analyze flutter evolution. Verified experimentally and numerically, the formulas explicitly explain why flutter speed reaches a global minimum when the mass center is slightly downstream of elastic center and the torsional-to-vertical frequency ratio is slightly above unity. Moving the mass center upstream sharply increases flutter speed until flutter ceases, while shifting it further downstream results in a more gradual rise. The global minimum flutter speed is predicted to be proportional to torsional frequency and weakly influenced by mass ratio; the existence of mass unbalance reduces this flutter speed by up to 36%. Structural damping strongly affects flutter speed near the global minimum but has less impact at large mass unbalance. Analytical solutions of flutter speed sensitivity to parameters are also derived. These formulas provide a practical predictive tool for flutter analysis, reducing reliance on wind tunnel testing and simulations, while offering clear guidelines for the design and optimization of flutter-prone structures and FEH systems.

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来源期刊

International Journal of Mechanical Sciences 工程技术-工程：机械

CiteScore

12.80

自引率

17.80%

发文量

769

审稿时长

19 days

期刊介绍： The International Journal of Mechanical Sciences (IJMS) serves as a global platform for the publication and dissemination of original research that contributes to a deeper scientific understanding of the fundamental disciplines within mechanical, civil, and material engineering. The primary focus of IJMS is to showcase innovative and ground-breaking work that utilizes analytical and computational modeling techniques, such as Finite Element Method (FEM), Boundary Element Method (BEM), and mesh-free methods, among others. These modeling methods are applied to diverse fields including rigid-body mechanics (e.g., dynamics, vibration, stability), structural mechanics, metal forming, advanced materials (e.g., metals, composites, cellular, smart) behavior and applications, impact mechanics, strain localization, and other nonlinear effects (e.g., large deflections, plasticity, fracture). Additionally, IJMS covers the realms of fluid mechanics (both external and internal flows), tribology, thermodynamics, and materials processing. These subjects collectively form the core of the journal's content. In summary, IJMS provides a prestigious platform for researchers to present their original contributions, shedding light on analytical and computational modeling methods in various areas of mechanical engineering, as well as exploring the behavior and application of advanced materials, fluid mechanics, thermodynamics, and materials processing.