Structural Safety Indices for Repeated Loads

Approximations for the distribution functions of the extremes in a number of repetitions of a random variable are developed based on the crossing approach. Results are obtained for independent repetitions and Gauss-Markov correlated sequences and processes. These approximations are combined with an approximate full-distribution structural safety index in a number of examples. It has been shown that correlation between consecutive load realizations can often be ignored in safety analysis for many situations of practical interest.