| Summary: | 碩士 === 淡江大學 === 土木工程學系 === 90 === The need of high-rise buildings in the highly populated area is growing due to the limited space. In addition, the development of high strength materials and the improvement of construction techniques have made the tall buildings with large slenderness to be designed and built. The increase of building height usually increases the susceptibility of the building to wind excitations. This phenomenon is more obvious for the high-rise buildings with large slenderness and low damping. Under strong wind excitations, the type of structures will obviously yield large deformations. For these reasons, the analysis should take into account the nonlinear effects to predict the structural responses. Since the nonlinearities are generally ignored in frequency domain, a time domain approach was used in this study.
An AR process will be used to transform the target frequency spectrum into a time domain for performing the nonlinear analysis to study the along wind response of high-rise buildings. At a design wind speed, the time-dependent wind loads at each floor will be calculated based on the distribution of mean wind speed and fluctuating wind speed along the height, and the admittance function. A finite element library consisted of beam-column elements and beam elements, modeling the columns and beams, is used to model the high-rise buildings to evaluate their time history responses under wind excitations.
By using this method, a 31-stories building subjected to dynamic wind loads was analyzed. Comparison of the results obtained from this proposed model and from the frequency domain analysis indicates that they are in good agreements.
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