Along - and across - wind load and vibrations of slender structures caused by wind direction fluctuations - Similarities and differences

摘要

Along - and across-wind loads on slender structures caused by oncoming wind turbulence (i.e. buffeting wind loads) consist of two terms. The first term corresponds to along-wimi velocity components u. The second one corresponds to across-wind velocity component v or, in other words, wind direction fluctuationsα. The formulae describing these two components are similar, however, values of fluctuating components of wind loading resulting from them may differ significantly. Similarities and differences concerning autocorrelation functions and power spectral density functions of generalized forces of along - and across-wind loads caused by wind direction fluctuations are discussed in detail. For simplification of the considerations carried out only the case of vertical slender structures with symmetrical cross-sections is analysed.