A Novel Constrained-Layer Damper for Vibration Mitigation of High-Mast Illumination Poles

This study proposes a novel constrained-layer damper (CLD) design for reducing buffeting-induced vibration on high-mast illumination poles (HMIPs). The conventional CLD utilizes a single-piece constraining layer, making it ineffective when applied to circular sections due to the overlapping neutral axes between the constraining layer and the base structure. To address this issue, the proposed CLD incorporates several longitudinal slits in the constraining layer such that the neutral axes of the slitted constraining layer are separated from the base structure. This design enables the viscoelastic layer to develop shear strain under the bending deformation of the base structure, thereby developing viscoelastic damping to mitigate vibrations. Comprehensive numerical simulations were conducted to examine the impact of different CLD parameters on damping enhancement for tubular structures, including the thickness of the viscoelastic layer, the thickness of the constraining layer, and the percentage of longitudinal coverage. The study found that the proposed CLD can increase the damping level of the HMIP to 235% of the inherent damping of the HMIP and reduce its steady-state response at resonance by 57%.