Probabilistic assessment of wind-sensitive structures with uncertain parameters

Studies of Davenport and others have provided the basis for a simple gust f actor approach to evaluate the wind-induced structural responses. This appr oach is based on the maximum responses that can be represented by their cor responding mean maximum response. However, the uncertainty in the wind char acteristics and in the material properties and geometry variables affects n ot only the mean maximum responses but also their variability. By consideri ng these uncertainties, estimates of the statistics of the maximum response s can be obtained from the unconditional probability distributions of the m aximum responses. Alternatively, they can be obtained directly from the unc ertainty propagation analysis based on the conditional mean maximum respons es. The fort-ner is accurate whereas the latter is an approximation. The ad equacy of this approximation and its effect on the structural reliability a re investigated. Results reported in this study seem to support that the use of the conditio nal maximum response equal to the mean maximum response is adequate for the uncertainty propagation analysis. Results of the reliability analyses also suggest that the consideration of the uncertainty in structural parameters such as the fundamental period of vibration and the damping ratio is very important for serviceability limit states, and that these uncertainties may be ignored for the resistance based limit states as long as the structure behaves linearly. (C) 2001 Elsevier Science Ltd. All rights reserved.