Reliability-based vector nonstationary random critical earthquake excitations for parametrically excited systems

摘要: Abstract The study considers the earthquake response of stack-like structures subjected to simultaneous action random horizontal and vertical acceleration components. governing equation motion in this case is approximated by a set coupled randomly time varying ordinary differential equations. components accelerations are modelled as nonstationary Gaussian processes that obtained multiplying deterministic modulating functions with partially specified stationary processes. Specifically, it assumed matrix power spectral density (psd) not known, while, variance, average rate zero crossings, entropy frequency range interest taken be known. unknown input psd determined such reliability index associated structure performance function minimized. solution procedure employed, combines theory Hasofer–Lind indices, surface modelling constrained nonlinear optimization tools. critical so leads definition excitation models produce least favorable response, which, at same time, possess few well known properties loads. A numerical example illustrates concepts developed reference chimney provided.