Analysis Of Fatigue Life Under Along-wind Loading Of High Rise Structure Considering Joint Distribution Of Wind Speed And Direction

With the wide application of high rise structures, it gains its importance. And in most case the control load of high rise structure is wind load. The fluctuating wind load may lead to fatigue failure of high rise structure in its breaking point, hence a reasonable design can not only help resisting the external load but also make full of the building materials. The basic wind pressure in current most wind design codes is based on 50-year return period, where directionality of wind speed is not taken into account. For the metal structures, this treatment also may miscalculate the structural fatigue life. Additionally, due to the unavailability of complete data, the possible shelter effect of wind speed on some directions appears in practice. This effect may result in underestimate the structural fatigue life. An assessment of long-term fatigue damage on a mast structure is presented in this paper considering the wind directionality. In this paper, as long as 13-year measured data from National Oceanic and Atmospheric Administration (NOAA) of USA is used here. In previous study, the duration of the data used for directionality is usually 4-5 years. The preceding data provide a good opportunity to study the directionality and the possible shelter effect on the structural fatigue life estimation. The data will be fitted to establish a joint probability density function of wind speed and direction. Furthermore, the influence of neglecting directionality and shelter effect is also studied. Results show that directionality may have noticeable effect on the fatigue life prediction of a mast structure. Also, shelter effect results in the remarkable influence. The five parts of this paper are as follows:1. The application of high rise structures is briefly introduced first. Modeling of joint distribution wind speed and direction and wind-induced fatigue of high rise structure are also reviewed here.2. Wind characteristic and its effect on the structure are described, then a introduction of fatigue and wind-induced fatigue of structure is made.3. After a preliminary treatment of original measured data, Weibull distribution and mixed distribution based on Kernel density estimation and Hermite polynomial model are used to fit the data respectively, and Comparison of the results is made.4. Wind field on different location of structure is generated by spectral representation method. The wind loads are acquired and applied on the finite element model of the structure. The fatigue damage results are compared with the data from field measurement.5. Fatigue life is calculated under different circumstances. Besides shelter effect of wind is also investigated here. And the fatigue life results are compared with those obtained by the close-form solution of fatigue life based on frequency domain.