On structural reliability under time-varying multi-parameter loading

Special attention will be paid to the superimposition of loads of different origin and characteristics (e.g. long-term loads like the furniture and usual occupancy load in a building and short-term loads like explosions, earthquakes, storms, etc.): it will be recognized that a single procedure for all cases does not appear practical, and that, within a general framework special method must be devised according to the type of loads and structural responses. For instance, the superimposition of impulsive loads must be studied with reference to the response time of the structure. It will be shown that usually, the statistics of extreme values are not sufficient for a correct study of superimposition: the instantaneous probability distributions of the load intensities are also required. The results obtained with respect to the loads can be joined with previous results by Augusti and Baratta (see e.g. SMiRT-2 paper M7/8) on structural strength, for the evaluation of the probability of success (i.e. the reliability) of a structural design