Tham khảo tài liệu 'wind tunnels and experimental fluid dynamics research part 12', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 20 A Computer-assisted Wind Load Evaluation System for the Design of Cladding of Buildings A Case study of Spatial Structures Yasushi Uematsu Tohoku University Japan 1. Introduction Thin sheet metal and or membrane are often used for roof cladding of spatial structures because of their strength and lightness Noguchi et al. 2003 . Being light and flexible such roofing materials are vulnerable to dynamic wind actions. Since wind pressures acting on spatial structures vary spatially as well as in time the design wind loads should be determined based on the dynamic characteristics of wind pressures. Fatigue of cladding elements such as roofing material and its fixings may play an important role in the wind resistant performance of cladding systems although it is seldom considered in the design. Roof cladding is usually designed based on the worst peak pressure coefficients irrespective of wind direction. The conventional codification provides a single peak design pressure coefficient for each roof zone considering a nominal worst-case scenario. Neither the probability distribution of the peak pressure coefficients nor the peaks other than the largest one are considered. Hence they are not suitable for fatigue and risk-consistent designs. Building design has recently shifted to a performance-oriented one. Therefore it is hoped to develop a new methodology that provides the peak pressure coefficients according to predetermined risk levels and the loading sequence for estimating the fatigue damage to roof cladding and its fixings. Computer simulation of wind pressure time series may be useful for this purpose. Kumar and Stathopoulos 1998 1999 2001 proposed a novel simulating methodology that generates both Gaussian and non-Gaussian wind pressure fluctuations on low building roofs. Despite its simple procedure the technique is successfully applied to fatigue analysis as well as to the evaluation of extreme pressures in a risk-consistent way. Therefore this technology is .
