Probability of Facility Damage From Extreme Wind Effects

Abstract

A probabilistic methodology has been developed to assess the risk of wind‐induced damage to structures and facilities. This methodology has been applied to a number of facilities and power plants in the United States for tornadoes, hurricanes, and straight‐wind storms. The wind effects considered include dynamic pressure, atmospheric pressure change, and wind‐borne missile impact loads. The facility structures and components are described by a reliability network, which is analyzed to provide the system failure probability considering all failure modes. Probabilistic Monte Carlo methods, coupled with variance reduction techniques, are used in the computations. The methodology requires site‐specific information on facility layout, missile sources, and wind frequencies. Three‐dimensional steady‐state windfields are modeled, and time‐history calculations of missile trajectories are used to predict the loading distributions on each structure. The model outputs include component and system damage probabilities for different levels of design protection and, for existing facilities, optimal upgrade and risk‐reduction strategies.