Wind Direction and Structural Reliability

Abstract

The effect of wind direction on structural reliability is studied as a problem of a vector wind force process outcrossing a structural resistance boundary which may be direction‐dependent. When the structural orientation is not known or the winds have no directionality but the resistance is highly direction‐dependent, results from simple parametric studies indicate that the upcrossing (or failure) rate is approximately proportional to the effective “direction window” width and there is a significant reduction in response level (or risk of failure) compared with the results based on a “worst direction” assumption. However, a lower bound exists to the outcrossing rate as the window vanishes. When the structural orientation is known and for location where winds show strong directionality the outcrossing rate and failure probability could be very sensitive to the structural orientation. Implications of the findings in the formulation of code procedures are mentioned.