A sensitivity-based approach for interval reliability analysis of structures under random excitation

The present study is devoted to the reliability analysis of linear discretized structures, with uncertain-but-bounded mass and stiffness parameters, subjected to stationary Gaussian multi-correlated random excitation. The reliability function for the extreme value stress process is evaluated in the framework of the first-passage theory. Due to the interval uncertainties affecting structural parameters, the reliability function is an interval function. The aim of the paper is to propose an efficient procedure for the evaluation of the bounds of the interval reliability function which provides a range of structural performance. To this aim, a sensitivity-based approach is applied. So operating, the dangerous overestimation of the solution, caused by the dependency phenomenon, is overcome. The main advantage of this approach is to provide appropriate combinations of the values of the uncertain-butbounded parameters which yield accurate predictions of the bounds of the interval reliability function for the extreme value stress process. A case study is analyzed to demonstrate the accuracy and efficiency of the presented method.