Development of an adaptive rolling tuned mass damper for structural vibration control under random directional excitation

In the natural environment, slender structures are often subjected to external loads, such as wind, which are random in direction. To mitigate such multi-directional vibrations, a novel Adaptive Rolling Tuned Mass Damper (ARTMD) is proposed. The device comprises a spherical oscillator, a track, a rotating bearing, and a hemispherical cavity. Through the inertial moment of the spherical oscillator, the rotating bearing enables the internal track of the ARTMD to adaptively align with the instantaneous displacement direction of the primary structure during vibration. To evaluate its adaptive damping performance, a dynamic model of a single-degree-of-freedom (SDOF) structure coupled with the ARTMD is established using the energy method. The ARTMD is optimally designed based on the H∞ criterion, with the objective of minimizing structural displacement response in the frequency domain. Subsequently, numerical simulations and experimental tests are conducted to examine the control performance and adaptive capability of the ARTMD on the SDOF structure. Results demonstrate that the ARTMD achieves significantly better vibration suppression than the conventional unidirectional Tuned Rolling Mass Damper (TRMD) when the excitation direction deviates from the damper track orientation, owing to its self-adjusting mechanism.