Probability Density Evolution Analysis of Nonlinear Seismic Response of Structures with Random Parameters Following Different Distributions

The randomness of structural parameters should be reasonably taken into account to assess the global performance of complex structures subjected to seismic actions. In the present paper, incorporating the generalized F-discrepancy (GF-discrepancy) based optimal point selection strategy and the probability density evolution method (PDEM), the effects of different distribution types and different coefficients of variation of the random parameters on the response of a multi-degree-of-freedom nonlinear structure with tens of random parameters are studied. The results show that the difference between the second-order moments of the structural responses with different types of distributions could be in the order of 30%. When the coefficients of variation of the basic parameters are either very small or fairly large, the effects of different types of distributions on the second-order moments of responses are relatively large, but in an opposite tendency. Therefore, there exists a range of the coefficients of variation in which the different types of distributions have little effects on the second-order moments of responses. However, the probability density functions (PDFs) of the responses are always affected considerably, even may change qualitatively by the types of distributions of the random parameters.