ABSTRACT
For the prediction of a building’s dynamic response at various wind speeds and directions, it is necessary to know the natural modes of vibration of the structure, including the natural frequencies and modal deflection shapes. It is also necessary to know the damping in each mode. In steel buildings, a somewhat similar behavior has been observed, which has been attributed to slippage occurring at connections as amplitudes increase. These changes will clearly affect the response to wind. The Non-Directional method is the simplest of the analysis methods, because it simply assumes that the T-year wind speed occurs from all directions, one of which will be the aerodynamically worst direction for the building. The focus of the Non-Directional and Sector Velocity methods is on extreme wind speeds, while what are needed in the end for design are extreme load effects.
