Lifetime risk of failure of steel building frames subjected to dynamic wind loading

Abstract

A method is presented for evaluating the lifetime risk of failure, in terms of probability of excessive inter-floor deflection, for a class of steel building frames subjected to dynamic wind loading. Wind loads are generated by a simulation technique using a power law profile and Davenport's gust spectrum model. Governing differential equations of motion are solved by a step-by-step integration method with the assumption of shear beam model and ideal elastoplastic force-deformation relationship. Generation of artificial samples of wind loading and corresponding time-histories of response followed by statistical analysis is repeated for a range of mean wind speeds that are likely to occur at a given location over the design lifetime of the structure. Lower and upper bound story drifts of 0.25% and 0.50% of story height are considered in the calculations. Numerical examples are presented to illustrate the application of the method which serves as a convenient checking procedure for examining the adequacy of a conventional design.