Wind induced responses of a hyperboloidal cooling tower in time-domain and gust effect factor analysis
ZHANG Junfeng1,2,GE Yaojun2,ZHAO Lin2
1. School of Civil Engineering, Zhengzhou University, Zhengzhou 450001, China;
2.State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China
Abstract：Studies were conducted for wind induced dynamic responses of a hyperboloidal cooling tower, gust factor g and dynamic amplification factor D of its different internal forces and displacements. The gust effect factor β, a concept of the equivalent wind load used for structural design was included as well. The tower's wind-induced dynamic analyses in time domain were conducted based on the wind pressure data obtained from wind tunnel tests on a rigid model of a large hyperboloidal cooling tower. The results showed that g and D of all responses both vary greatly with tower shell positions in latitude and meridian directions, and therefore they cant be applied in practice conveniently; however, the two dimensional distributions of g and D can both be simplified into one dimensional distributions just along meridian height; this simplification is based on the characteristics of time domain responses, structure behavior and structural design principles; meanwhile, the amplitudes of D can be applied practically but the application method is not consistent with that of the current design codes; furthermore, according to the structural design independence in latitude and meridian directions and different weights of wind induced internal forces in structural design, two Ds are adopted for the internal forces in latitude and meridian directions, respectively, but the former is much higher than the latter; consequently, the two Ds can be used as βs in the two directions, respectively in structural design as usual.
