Wind Load Characteristics And Windinduced Response Of Arch-supported Membrane Structure

Tensile membrane structures are gaining popularity these days because of their aesthetic architecture and high structural functionality.Lightweight and flexible nature of tensile membrane structure make them highly vulnerable to wind load.But current standards and codes cannot provide the design specification of doubly-curved tensile membrane structure.So,it is necessary to conduct in-depth research on these newly invented structures to set generalized design methodology and to prevent catastrophic damage.Based on the rigid model wind tunnel test,the wind load characteristic and windinduced response analysis are presented on elliptical and rectangular-shaped archsupported membrane structure.Regional wind shape and wind vibration coefficient,proposed in this thesis,can be used in the modification of codes and standards.Main contents of thesis include:Geometrical parameters of rigid models are defined based on the related engineering projects.Rigid model wind tunnel experiment is carried out under different flow fields.Influence of different parameters on mean and fluctuating wind pressure coefficient are studied.The results show that distribution of wind load depends greatly on wind direction,wind flow field,rise-span ratio and boundary walls.And variation is quite distinctive in windward area.Both elliptical and rectangular-shaped structure experience larger suction and fluctuating wind pressure coefficient under oblique wind flow.Moreover,regional wind shape coefficient is put forward which provides reference for the design of membrane structures.Wind-induced response analysis is carried out by using random vibration time history analysis method.Parametric analysis is performed to find the effect of different key parameters on wind-induced response.Results show that peak responses increase significantly with wind speed and arch length.Effect of wind direction is quite complex in case of elliptical-shaped structure.Increasing the pre-tension can improve the windresistant performance,but the effect is limited.Peak response increases as rise-span ratio increases,but the rate of incensement is not uniform.Effect of boundary walls on peak response is quite complex,and it depends greatly on wind direction and rise-span ratio.Wind resistant design method is presented based on the gust loading factor and nonlinear adjustment factor.Gust loading factors of different responses,including displacement,membrane stress,cable internal force and reaction force,are calculated considering the effect of different parameters such as length of arch,rise-span ratio and membrane pre-tension.Then,probabilistic gust loading factor and nonlinear adjustment factor are proposed for elliptical and rectangular-shaped arch-supported membrane structure.The result shows that the coefficients of open structure are relatively larger than closed one.