Practical Approach to Digitally Simulate Nonsynoptic Wind Velocity Profiles and Its Implications on the Response of Monopole Towers

Abstract

In the numerical simulation of stochastic nonstationary wind loads, rapidly varying wind speed fluctuations about a deterministic mean value typically represent the sole source of random variability. Adopted in deterministic-stochastic methods, this assumption may not fully capture the aleatory nature of a hazard, especially for nonsynoptic outflows such as intense thunderstorms or microbursts with noticeable nose-like mean wind velocity profiles that vary with each occurrence. Such profiles depart from the theory of atmospheric boundary layers. To introduce additional randomness in the digital simulation of these nonsynoptic wind fields and loads, a numerical procedure was developed in this study to generate unique realizations of analytical functions that describe changes in mean wind velocities with elevation. The utility of the proposed procedure for performance-based wind engineering (PBWE) is demonstrated for the fragility analysis of two monopole towers subjected to loads from nonsynoptic thunderstorm outflows.