ANALYSIS AND SIMULATION TOOLS FOR WIND ENGINEERING

This paper examines state-of-the-art analysis and simulation tools for applications to wind engineering, introduces improvements recently de veloped by the authors, and directions for future work. While the scop e of application extends to a variety of environmental loads (e.g. oce an waves and earthquake motions), particular reference is made to the analysis and simulation of non-Gaussian features as they appear in win d pressure fluctuations under separated flow regions and non-stationar y characteristics of wind velocity fluctuations during a gust front, a thunderstorm or a hurricane. A particular measured non-Gaussian press ure trace is used as a focal point to connect the various related topi cs herein. Various methods of non-linear system modeling are first con sidered. Techniques are then presented for modeling the probability de nsity function of non-Gaussian processes. These include maximizing the entropy functional subject to constraints derived from moment informa tion, Hermite transformation models, and the use of the Kac-Siegert ap proach based on Volterra kernels. The implications of non-Gaussian loc al wind loads on the prediction of fatigue damage are examined, as wel l as new developments concerning gust factor representation of non-Gau ssian wind loads. The simulation of non-Gaussian processes is addresse d in terms of correlation-distortion methods and application of higher -order spectral analysis. Also included is a discussion of preferred p hasing, and concepts for conditional simulation in a non-Gaussian cont ext. The wavelet transform is used to decompose random processes into localized orthogonal basis functions, providing a convenient format fo r the modeling, analysis, and simulation of non-stationary processes. The work in these areas continues to improve our understanding and mod eling of complex phenomena in wind related problems. The presentation here is for introductory purposes and many topics require additional r esearch. It is hoped that introduction of these powerful tools will ai d in improving the general understanding of wind effects on structures and will lead to subsequent application in design practice. Copyright (C) 1996 Elsevier Science Ltd.