Stochastic uncertainty quantification of seismic performance of complex large-scale structures using response spectrum method

Imprecision and uncertainty always exist in engineering structures. In recent years, an increasing emphasis is placed on quantifying structural performance by explicitly modeling uncertainties. A limited number of studies have been conducted on the uncertain analysis of complex structures. Because the time-history response analysis (THRA) is extremely time-consuming to solve uncertain problems of complex structures, a stochastic finite element method (SFEM) using response spectrum analysis (RSA) has been developed to analyze full-scale lattice dome structures with uncertain variables in this paper. Based on the proposed method, the lattice dome structure under different earthquake intensity levels is investigated and the probabilistic structural demands are quantified. Compared with the perfect dome, the results show that the mean deformations and reaction force values at supports caused by earthquakes increase in the uncertain dome and the mean axial force values of the members decrease. The structural demands present larger uncertain intervals with the increase in earthquake intensity, thus, the calculation results in the deterministic analyses can be further improved by the uncertainty quantification. Finally, the effects of uncertain variables on the structural demands are discussed. Unlike the findings in the THRA, the structural imperfections are the most important factor affecting structural performance in the RSA. Moreover, compared with THRA, a larger sample size can be used in the RSA to predict the seismic performance of complex structures with higher precision. This study provides possible applications for the probability-based performance analysis of other large-scale structures with uncertain parameters.