Three-dimensional probabilistic wind-borne debris trajectory model for building envelope impact risk assessment

This paper presents a probabilistic debris trajectory model adapted from current 6-degree-of-freedom (6-DoF) deterministic models, in which the aleatoric (inherent) uncertainty is explicitly considered in the proposed probabilistic model. While the inherent randomness in the debris flight trajectory is irreducible due to the wind turbulence, variation in wind direction, gustiness of the wind event, and so forth, the proposed probabilistic model seeks to address these uncertainties through Monte Carlo simulations with the appropriate statistical distributions applied to the governing equations of motion of the debris. Calibration of the probabilistic debris trajectory model is performed through an analytical and visual comparison of the simulated data to wind tunnel test data. Reasonable agreement is observed between the simulated and the wind tunnel test debris landing locations, thus confirming the applicability of the probabilistic wind-borne debris model. The proposed probabilistic model provides an effective method for predicting the variation of debris trajectories in a three-dimensional (3D) space, which is imperative when performing regional building envelope impact risk assessments in which a large amount of debris sources and targets must be considered in the simulation.