Fragility of steel transmission monopoles under hurricane wind loading: Part II - Dynamic framework and comparative assessment

This preprint extends the parametric fragility framework of Part I to the dynamic response of steel transmission monopoles to turbulent hurricane wind. Wind loads are described by Kaimal spectra, the response is obtained by modal superposition, and failure is the first exceedance of the age-degraded bending capacity within a storm of given duration, which enters the closed-form fragility equations as a fifth variable. For 230 kV single-circuit and double-circuit poles, 1207 matched pairs of static and dynamic fragility curves show that the dynamic analysis gives higher median failure wind speeds over most of the range of the variables, with a median difference over the pairs of +10.1% (single circuit) and +13.6% (double circuit). This is a preprint of a working paper and serves as a project report of the Atlantic Marine Energy Center (AMEC). It has not been peer reviewed.