Abstract
In this paper, a simplified screening method for a pole structure such as electric pole, light pole, signal pole, etc., using a modal-based evaluation of the structural local flexibility is proposed. A ratio of the rotational local flexibility of the healthy part to that of the potentially damaged root part is adopted as a damage index, and its approximate calculation scheme is proposed. Using the proposed method, one may quantitatively evaluate the extent of the damages in the root part of the pole by conducting a vibration test identifying the first few modes. By calculating the modal parameters in two directions perpendicular to the longitudinal axis, it is possible to identify the change of the cross-sectional principal axis due to the damage as well as the imparted additional flexibility with respect to the principal axis. Finally, the influence of the identification error of the modal parameters to the damage evaluation is numerically investigated.
