Combined dynamic effects of correlated load processes

A large number of loadings on structures, particularly nuclear structures, are random and dynamic in nature and may be generated from common or related sources (e.g., storms, earthquakes, and accidents). The combination of load effects which may be nonlinear, dynamic and statistically dependent is therefore an important issue in the assessment of safety and performance of a nuclear structure over its lifetime. This paper summarizes the latest developments in this area with emphasis on the versatile method of analysis based on a consideration of load coincidence. The validity and accuracy of this method is established by comparison with other methods and Monte Carlo simulations. Parametric studies are carried out and effects of dynamic response and load dependencies are examined. The accuracies of some of load combination rules are also studied and ranges of validity of each rule are identified such that some risk-consistency can be achieved if such rules are to be used. (orig.)