Dynamic Characteristics and Parametric Study of Vibration Dampers Based on Modal Simulation

Dampers are important components for suppressing wind-induced vibrations in transmission lines, and their dynamic characteristics directly affect vibration damping performance. This paper studies FD-type, FR-type, and FDNJ-type dampers. By establishing three-dimensional finite element models, their natural frequencies, mode shapes, and the effects of structural parameters were systematically investigated using methods including equivalent Young’s modulus identification, modal analysis, and transient response simulation. First, based on cantilever beam theory, the formula for the equivalent Young’s modulus of stranded wires was derived, addressing the accuracy issue in modeling the stranded wire structure. Subsequently, modal analysis was conducted on the three types of dampers to obtain their multi-order natural frequencies and mode shapes. Then, the effects of key parameters such as stranded wire length and hammer diameter on natural frequency and energy dissipation were systematically studied. In the study, the block Lanczos method was used for modal analysis to ensure the accuracy and convergence of the simulation results, and transient dynamic analysis was conducted based on the Newmark-β method, with a time step set to 1e-4 s to capture the subtle dynamic responses of the damper. The results show that FD-type, FDNJ-type, and FR-type dampers have 2, 3, and 4 main resonance frequencies, respectively. The length of the stranded wire is negatively correlated with the resonance frequency and positively correlated with energy dissipation. Increasing the hammer head diameter also reduces the frequency. In addition, parameter sensitivity analysis shows that the length of the suspended conductor has the greatest impact on the first-order resonance frequency and energy dissipation capability, while the diameter of the hammer head has a more significant effect on adjusting the second-order resonance frequency. By adjusting structural parameters, the natural frequency of the vibration damper can be custom-designed. This study provides a theoretical basis for the structural optimization and engineering selection of vibration dampers.