Lifetime-Oriented Structural Design Concepts- P3: At the beginning of 1996, the Cooperative Research Center SFB 398 financially supported by the German Science Foundation (DFG) was started at Ruhr-University Bochum (RUB). A scientists group representing the fields of structural engineering, structural mechanics, soil mechanics, material science, and numerical mathematics introduced a research program on “lifetimeoriented design concepts on the basis of damage and deterioration aspects”. | Wind Actions 17 Fig. . Distribution of absolute frequencies of normalized gust responses into subsequent classes of different levels of effect M F N is the reference value Mk an Nk are characteristic internal forces of a construction component W is the elastic section modulus A is the loaded area. Stress levels between Aa and Aa can occure times in 50 years in the statistical mean. A damage accumulation after Palmgren-Miner D 2j Nj Nci is performed in order to assess resistance of the considered component with respect to fatigue. Figure shows an example taken from a fatigue analysis of the Fig. . Comparison of the distribution of cyclic stress amplitudes with the S-N curve Wohler curve of stress concentration category 36 after 30 18 2 Damage-Oriented Actions and Environmental Impact gust responses of steel archs of a road bridge. The considered cerb is sufficient to resist the repeated gust impacts. The application of the Equations or permits a detailed and safe method for the fatigue analysis of gust-induced effects at building structures. Influence of Wind Direction on Cycles of Gust Responses Authored by Rudiger Hoffer and Hans-Jürgen Niemann Meteorological observations document that the intensity of a storm is strongly related to its wind direction. Figure a shows the wind rosette of the airport Hannover Germany as an example. The probability of the first passage of the same threshold value can strongly vary for different sectors of wind direction. That means that the risk of a high wind induced stressing of a structural component is different between the wind directions. The failure risk Fig. . Rosettes of wind quantities at Hannover 12 sectors 50 years return period a extremes of 10-minutes means of wind velocities at the airport of Hannover at reference height of 10 m above ground b extremes of 10-minutes means of wind velocities at a building location at building height of 35 m above ground c extremes of
