The Characteristics Of Wind Load And Design Wind Load On Cladding Of Dome Roof

Dome roof structures are widely used in engineering, these structures are very sensitive to wind load because of the large span, light weight, low damp and low natural frequency, therefore the wind load on the roofs is often the control load in the design of the structure. The knowledge of the wind load on dome roofs is far from deep. The design wind load on cladding of dome roof which is proposed by Chinese load code can not guarantee the safety of the roof because it does not consider the impact of the signature turbulence to wind load on roof. In view of this, based on the data obtained from wind tunnel test, this paper makes an analysis of the characteristics of wind pressure distribution and signature turbulence on dome roofs, furthermore, this paper proposes a new formula to calculate the design wind load on cladding of dome roofs on the basis of the analysis of extreme value of non-Gaussian wind pressure. The main contents are as follows:(l)The characteristics of wind pressure distribution and signature turbulence on five different rise-span ratios dome roofs are analyzed, then the variation of which with the rise-span ratio is summarized; based on the analysis of wind pressure spectrum, correlation coefficient and coherence function, further understandings of the signature turbulence on dome roofs have been acquired.(2)The phenomena of non-Gaussian wind load on dome roofs are described and the causes of which are explained. The third and fourth order statistical moments of wind pressures are employed to obtain a description and measurement of the non-Gaussian features, and to locate regions with non-Gaussian features on dome roofs.(3)Using Hermite moment model theory, the extreme values of non-Gaussian wind pressure on dome roofs are calculated, then the characteristics of distribution and mechanisms of which are analyzed systematically, in addition, the causes of extreme wind suction are explained. The results indicate that the biggest extreme values of wind suction appear on the windward eaves of small rise-span ratio dome roofs and leeward eaves of large rise-span ratio dome roofs.(4)In view of the unreasonableness of the design wind load on cladding of dome roofs which is proposed by Chinese load code, this paper put forward a new formula to calculate the design wind load and then divides the design wind load on dome roofs, providing guidance for the wind-resistant design of dome roofs.