The problem of evaluating the probability that a structure becomes unsafe under acombination of loads, over a given time period, is addressed. The loads and load effectsare modeled as either pulse (static problem) processes with random occurrence time, intensity and a specified shape or intermittent continuous (dynamic problem) processes whichare zero mean Gaussian processes superimposed 'on a pulse process. The load coincidencemethod is extended to problems with both nonlinear limit states and dynamic responses,including the case of correlated dynamic responses. The technique of linearization of anonlinear limit state commonly used in a time-invariant problem is investigated for timevaryingcombination problems, with emphasis on selecting the linearization point. Resultsare compared with other methods, namely the method based on upcrossing rate, simplercombination rules such as Square Root of Sum of Squares and Turkstra's rule. Correlatedeffects among dynamic loads are examined to see how results differ from correlated staticloads and to demonstrate which types of load dependencies are most important, i.e., affect'the exceedance probabilities the most.Application of the load coincidence method to code development is briefly discussed.
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