Modeling and Simulation of Transient Wind Load Effects

Notwithstanding the developments made in recent decades in wind effects on structures, there is a need to revisit the current paradigms and to look for improved understanding concerning the nature of wind field, associated aerodynamics and the resulting load effects in light of the emerging themes: non-stationarity/non-homogeneity/transient wind events; mechanical/convective turbulence; unsteady/transient aerodynamics. This paper discusses these issues and illustrates their significance as the next frontiers in wind engineering, current progress and activities at the NatHaz Modeling Laboratory to address this challenge. The “Gust Front Factor” is introduced that follows codes and standards based description of wind loads and it accounts for the following features: variation in the velocity profile; dynamics effects introduced by the sudden rise in wind speed (pulse effect); nonstationarity (amplitude/frequency modulations) of turbulence in gust fronts; transient aerodynamics.