Spectral Analysis Of Wind-induced Response For Pole-type Structure

In ocean engineering, wind load is usually about ten percent of all loads on ocean structure. In most cases, it is only estimated without precise calculation. It needs to detailed calculate wind load and analyze vibration, taking into account fatigue and stabilization in structure. Some new sorts of structures coming forth with modern material and construction technical have big flexibleness, small damp and light weight, wind load has an important even crucial status in all loads of the structures, so it is very necessary on ocean engineering for calculating wind load and analyzing vibration.Calculating wind load and analyzing vibration have two methods, time area and frequency area. Method of time area can put up linear and non-linear analysis, reflect structure characteristic more directly, gain more information about fatigue, but calculating formula of time area is very complex and it is not fit for practical engineering; method of frequency area only can put up linear and linearization analyze, but it is widely applied for its simple calculation and fit for engineering precision.This paper making use of basic theory of wind engineering and stochastic vibration place emphases on discussing wind load calculation and vibration analysis on pole-type structures. For pole-type structures in ocean engineering, the fundamental natural frequency is relatively low. The coupling effect between wind and structures can't be neglected. Morison equation, originally used for wave loads, is shifted into calculating wind load. By introducing aerodynamic damping, the coupling effect is considered. Based on this method, the first-three order frequency response function of vibration and correspond displacement spectrums are calculated in downwind direction. In crosswind direction, the influence of vortex shedding for pole-type structures with different geometrical parameters is analyzed, the method for calculating crosswind response is presented.