Trajectories of Wind-Borne Debris in Horizontal Winds and Applications to Impact Testing

This paper considers the trajectories of compact and rod-type wind-borne debris in horizontal winds, using a combination of experimental and numerical studies. These types are representative of the roof gravel and timber members currently used for testing building facades and storm shutters. These studies indicate that the ratio of horizontal debris speed to wind gust speed is primarily a function of the horizontal distance traveled by the debris as it accelerates toward the wind speed. Empirical expressions to approximate the horizontal speed of these debris as a function of travel distance and time are developed, and may be used to establish rational debris impact criteria.