DYNAMIC GUST RESPONSE OF INCLINED TOWERS

The classical stochastic dynamic analysis of line-like structures is extended to the case of a lattice tower with axis inclined to the vertical, for example all inclined flare tower. Attention is concentrated on the quasi-resonant response which is expressed in terms of geometric influence factors applicable to the spectral ordinates of a set of orthogonal turbulence components, together with effective length scales of the respective normalised co-spectra for separations along the tower axis. The turbulence can be regarded as isotropic in the relevant frequency range. The effective length scales for general inclination to the mean wind direction are considered in detail. The implications for fatigue checking a typical tower are considered in conclusion.