Wind-Induced Vibration Response of Substation Pillar-Type Switch Structures Based on Wind Tunnel Tests

To investigate the wind-induced vibration characteristics of the high-voltage Disconnect Switch (DS) system in the switching-off state and quantitatively evaluate the contribution of higher-order modes to the overall structural response, this study employed the finite element software ABAQUS to perform dynamic analysis of a refined finite element model of the treble-columns part of the DS system. The wind loads’ spectral densities corresponding to translational degrees of freedom in the [Formula: see text]- and [Formula: see text]-directions and torsional motion about the [Formula: see text]-axis were derived. These were used to obtain the generalized force mode correction coefficients for various directions and modal orders. Subsequently, the wind-induced vibration responses were calculated using the frequency domain method applied to a simplified multi-degree-of-freedom model of a serially connected three-column structure. Based on including contributions from higher-order modes, the resulting responses were combined using the Square Root of Sum of Square (SRSS) method to determine the overall distribution of wind-induced responses under different wind directions. The results reveal that the modal response distribution is relatively sparse, indicating that the effect of three-dimensional wind coupling can be neglected in the structural wind response analysis. Under the switching-off state, the resonant component of the pulsating wind response in both the [Formula: see text]- and [Formula: see text]-directions dominates over the background component. The most unfavorable wind direction angles for displacement and acceleration responses are [Formula: see text] and [Formula: see text] in the [Formula: see text]-direction, and [Formula: see text] and [Formula: see text] in the [Formula: see text]-direction, respectively. While the first-order mode is sufficient for accurate displacement response predictions, the contributions of higher-order modes must be considered for both acceleration and internal force responses.