Gust-front factor: A new framework for the analysis of wind load effects in gust-fronts
نویسندگان
چکیده
In comparison with atmospheric boundary-layer winds, which are customarily treated as stationary, gust-front winds such as a thunderstorm/downburst exhibit strong nonstationarity. In storms characterized by a gust-front, wind speed changes rapidly during a short time period. In order to realistically describe attendant loads effects, a new analysis framework is presented which is named the gust-front factor (GG-F) approach. The gust-front factor, akin to the gust loading factor in boundary-layer winds which has world-wide acceptance in codes and standards, is introduced and can be utilized in conjunction with the existing design standards. The GG-F based approach encapsulates both static and dynamic characteristics of gust-front wind effects on structures through the following features that distinguish them from conventional boundary-layer flows: variation in the vertical velocity profile; dynamic effects induced by the sudden rise in wind speed; non-stationarity of turbulence in gust-front wind; transient aerodynamics.
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