Vibration reduction research of a thin beam system by employing distributed coupling nonlinear energy sinks

In engineering applications, complex structural forms can often be approximated by coupled beam systems, underscoring the critical importance of vibration control in these structures. Leveraging the advantages of distributed nonlinear energy sinks (NES) in structural vibration management, this study introduces a distributed coupling nonlinear energy sink (CNES) into thin beam systems (TBS) and investigates its efficacy in reducing vibrations. A mathematical model of TBS incorporating distributed CNES is developed, and the Galerkin truncation method (GTM) is utilized to analyze TBS vibration response under harmonic excitation, confirming model accuracy. The effects of core parameters within the distributed CNES on the vibration reduction performance of TBS are systematically analyzed. Furthermore, the influence of varying distribution quantities of the distributed CNES on vibration behavior is also investigated. Numerical simulations reveal that optimized parameters for distributed CNES significantly enhance the vibration reduction ratio of TBS. However, certain parameter values may induce unconventional vibrational phenomena. This study finds that adjusting the distribution density of NES can not only mitigate these unconventional vibrations but also substantially boost vibration reduction efficacy. Compared to single CNES, distributed CNES offers a robust solution for controlling nonlinear-induced unconventional vibrations, allowing for effective vibration suppression in TBS without altering their intrinsic vibration characteristics.